diff --git a/core/java/android/window/TaskFragmentCreationParams.java b/core/java/android/window/TaskFragmentCreationParams.java
index 81ab7836435d8..c9ddf92d37407 100644
--- a/core/java/android/window/TaskFragmentCreationParams.java
+++ b/core/java/android/window/TaskFragmentCreationParams.java
@@ -20,6 +20,7 @@ import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
 import static android.app.WindowConfiguration.WindowingMode;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.TestApi;
 import android.graphics.Rect;
 import android.os.IBinder;
@@ -57,14 +58,33 @@ public final class TaskFragmentCreationParams implements Parcelable {
 
     /** The initial windowing mode of the TaskFragment. Inherits from parent if not set. */
     @WindowingMode
-    private int mWindowingMode = WINDOWING_MODE_UNDEFINED;
+    private final int mWindowingMode;
+
+    /**
+     * The fragment token of the paired primary TaskFragment.
+     * When it is set, the new TaskFragment will be positioned right above the paired TaskFragment.
+     * Otherwise, the new TaskFragment will be positioned on the top of the Task by default.
+     *
+     * This is different from {@link WindowContainerTransaction#setAdjacentTaskFragments} as we may
+     * set this when the pair of TaskFragments are stacked, while adjacent is only set on the pair
+     * of TaskFragments that are in split.
+     *
+     * This is needed in case we need to launch a placeholder Activity to split below a transparent
+     * always-expand Activity.
+     */
+    @Nullable
+    private final IBinder mPairedPrimaryFragmentToken;
 
     private TaskFragmentCreationParams(
-            @NonNull TaskFragmentOrganizerToken organizer,
-            @NonNull IBinder fragmentToken, @NonNull IBinder ownerToken) {
+            @NonNull TaskFragmentOrganizerToken organizer, @NonNull IBinder fragmentToken,
+            @NonNull IBinder ownerToken, @NonNull Rect initialBounds,
+            @WindowingMode int windowingMode, @Nullable IBinder pairedPrimaryFragmentToken) {
         mOrganizer = organizer;
         mFragmentToken = fragmentToken;
         mOwnerToken = ownerToken;
+        mInitialBounds.set(initialBounds);
+        mWindowingMode = windowingMode;
+        mPairedPrimaryFragmentToken = pairedPrimaryFragmentToken;
     }
 
     @NonNull
@@ -92,12 +112,22 @@ public final class TaskFragmentCreationParams implements Parcelable {
         return mWindowingMode;
     }
 
+    /**
+     * TODO(b/232476698): remove the hide with adding CTS for this in next release.
+     * @hide
+     */
+    @Nullable
+    public IBinder getPairedPrimaryFragmentToken() {
+        return mPairedPrimaryFragmentToken;
+    }
+
     private TaskFragmentCreationParams(Parcel in) {
         mOrganizer = TaskFragmentOrganizerToken.CREATOR.createFromParcel(in);
         mFragmentToken = in.readStrongBinder();
         mOwnerToken = in.readStrongBinder();
         mInitialBounds.readFromParcel(in);
         mWindowingMode = in.readInt();
+        mPairedPrimaryFragmentToken = in.readStrongBinder();
     }
 
     /** @hide */
@@ -108,6 +138,7 @@ public final class TaskFragmentCreationParams implements Parcelable {
         dest.writeStrongBinder(mOwnerToken);
         mInitialBounds.writeToParcel(dest, flags);
         dest.writeInt(mWindowingMode);
+        dest.writeStrongBinder(mPairedPrimaryFragmentToken);
     }
 
     @NonNull
@@ -132,6 +163,7 @@ public final class TaskFragmentCreationParams implements Parcelable {
                 + " ownerToken=" + mOwnerToken
                 + " initialBounds=" + mInitialBounds
                 + " windowingMode=" + mWindowingMode
+                + " pairedFragmentToken=" + mPairedPrimaryFragmentToken
                 + "}";
     }
 
@@ -159,6 +191,9 @@ public final class TaskFragmentCreationParams implements Parcelable {
         @WindowingMode
         private int mWindowingMode = WINDOWING_MODE_UNDEFINED;
 
+        @Nullable
+        private IBinder mPairedPrimaryFragmentToken;
+
         public Builder(@NonNull TaskFragmentOrganizerToken organizer,
                 @NonNull IBinder fragmentToken, @NonNull IBinder ownerToken) {
             mOrganizer = organizer;
@@ -180,14 +215,29 @@ public final class TaskFragmentCreationParams implements Parcelable {
             return this;
         }
 
+        /**
+         * Sets the fragment token of the paired primary TaskFragment.
+         * When it is set, the new TaskFragment will be positioned right above the paired
+         * TaskFragment. Otherwise, the new TaskFragment will be positioned on the top of the Task
+         * by default.
+         *
+         * This is needed in case we need to launch a placeholder Activity to split below a
+         * transparent always-expand Activity.
+         *
+         * TODO(b/232476698): remove the hide with adding CTS for this in next release.
+         * @hide
+         */
+        @NonNull
+        public Builder setPairedPrimaryFragmentToken(@Nullable IBinder fragmentToken) {
+            mPairedPrimaryFragmentToken = fragmentToken;
+            return this;
+        }
+
         /** Constructs the options to create TaskFragment with. */
         @NonNull
         public TaskFragmentCreationParams build() {
-            final TaskFragmentCreationParams result = new TaskFragmentCreationParams(
-                    mOrganizer, mFragmentToken, mOwnerToken);
-            result.mInitialBounds.set(mInitialBounds);
-            result.mWindowingMode = mWindowingMode;
-            return result;
+            return new TaskFragmentCreationParams(mOrganizer, mFragmentToken, mOwnerToken,
+                    mInitialBounds, mWindowingMode, mPairedPrimaryFragmentToken);
         }
     }
 }
diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizer.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizer.java
index d7d43aa19757b..b910287aa5358 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizer.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizer.java
@@ -133,8 +133,18 @@ class JetpackTaskFragmentOrganizer extends TaskFragmentOrganizer {
         }
 
         // Create a TaskFragment for the secondary activity.
-        createTaskFragmentAndStartActivity(wct, secondaryFragmentToken, ownerToken,
-                secondaryFragmentBounds, windowingMode, activityIntent,
+        final TaskFragmentCreationParams fragmentOptions = new TaskFragmentCreationParams.Builder(
+                getOrganizerToken(), secondaryFragmentToken, ownerToken)
+                .setInitialBounds(secondaryFragmentBounds)
+                .setWindowingMode(windowingMode)
+                // Make sure to set the paired fragment token so that the new TaskFragment will be
+                // positioned right above the paired TaskFragment.
+                // This is needed in case we need to launch a placeholder Activity to split below a
+                // transparent always-expand Activity.
+                .setPairedPrimaryFragmentToken(launchingFragmentToken)
+                .build();
+        createTaskFragment(wct, fragmentOptions);
+        wct.startActivityInTaskFragment(secondaryFragmentToken, ownerToken, activityIntent,
                 activityOptions);
 
         // Set adjacent to each other so that the containers below will be invisible.
@@ -173,8 +183,21 @@ class JetpackTaskFragmentOrganizer extends TaskFragmentOrganizer {
      */
     void createTaskFragment(@NonNull WindowContainerTransaction wct, @NonNull IBinder fragmentToken,
             @NonNull IBinder ownerToken, @NonNull Rect bounds, @WindowingMode int windowingMode) {
-        final TaskFragmentCreationParams fragmentOptions =
-                createFragmentOptions(fragmentToken, ownerToken, bounds, windowingMode);
+        final TaskFragmentCreationParams fragmentOptions = new TaskFragmentCreationParams.Builder(
+                getOrganizerToken(), fragmentToken, ownerToken)
+                .setInitialBounds(bounds)
+                .setWindowingMode(windowingMode)
+                .build();
+        createTaskFragment(wct, fragmentOptions);
+    }
+
+    void createTaskFragment(@NonNull WindowContainerTransaction wct,
+            @NonNull TaskFragmentCreationParams fragmentOptions) {
+        if (mFragmentInfos.containsKey(fragmentOptions.getFragmentToken())) {
+            throw new IllegalArgumentException(
+                    "There is an existing TaskFragment with fragmentToken="
+                            + fragmentOptions.getFragmentToken());
+        }
         wct.createTaskFragment(fragmentOptions);
     }
 
@@ -189,18 +212,6 @@ class JetpackTaskFragmentOrganizer extends TaskFragmentOrganizer {
         wct.reparentActivityToTaskFragment(fragmentToken, activity.getActivityToken());
     }
 
-    /**
-     * @param ownerToken The token of the activity that creates this task fragment. It does not
-     *                   have to be a child of this task fragment, but must belong to the same task.
-     */
-    private void createTaskFragmentAndStartActivity(@NonNull WindowContainerTransaction wct,
-            @NonNull IBinder fragmentToken, @NonNull IBinder ownerToken, @NonNull Rect bounds,
-            @WindowingMode int windowingMode, @NonNull Intent activityIntent,
-            @Nullable Bundle activityOptions) {
-        createTaskFragment(wct, fragmentToken, ownerToken, bounds, windowingMode);
-        wct.startActivityInTaskFragment(fragmentToken, ownerToken, activityIntent, activityOptions);
-    }
-
     void setAdjacentTaskFragments(@NonNull WindowContainerTransaction wct,
             @NonNull IBinder primary, @Nullable IBinder secondary, @Nullable SplitRule splitRule) {
         WindowContainerTransaction.TaskFragmentAdjacentParams adjacentParams = null;
@@ -238,22 +249,6 @@ class JetpackTaskFragmentOrganizer extends TaskFragmentOrganizer {
         wct.setCompanionTaskFragment(secondary, finishSecondaryWithPrimary ? primary : null);
     }
 
-    TaskFragmentCreationParams createFragmentOptions(@NonNull IBinder fragmentToken,
-            @NonNull IBinder ownerToken, @NonNull Rect bounds, @WindowingMode int windowingMode) {
-        if (mFragmentInfos.containsKey(fragmentToken)) {
-            throw new IllegalArgumentException(
-                    "There is an existing TaskFragment with fragmentToken=" + fragmentToken);
-        }
-
-        return new TaskFragmentCreationParams.Builder(
-                getOrganizerToken(),
-                fragmentToken,
-                ownerToken)
-                .setInitialBounds(bounds)
-                .setWindowingMode(windowingMode)
-                .build();
-    }
-
     void resizeTaskFragment(@NonNull WindowContainerTransaction wct, @NonNull IBinder fragmentToken,
             @Nullable Rect bounds) {
         if (!mFragmentInfos.containsKey(fragmentToken)) {
diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
index 6f9a4ff8188a5..d3dc05fb92d4b 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
@@ -1218,14 +1218,14 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
     TaskFragmentContainer newContainer(@NonNull Activity pendingAppearedActivity,
             @NonNull Activity activityInTask, int taskId) {
         return newContainer(pendingAppearedActivity, null /* pendingAppearedIntent */,
-                activityInTask, taskId);
+                activityInTask, taskId, null /* pairedPrimaryContainer */);
     }
 
     @GuardedBy("mLock")
     TaskFragmentContainer newContainer(@NonNull Intent pendingAppearedIntent,
             @NonNull Activity activityInTask, int taskId) {
         return newContainer(null /* pendingAppearedActivity */, pendingAppearedIntent,
-                activityInTask, taskId);
+                activityInTask, taskId, null /* pairedPrimaryContainer */);
     }
 
     /**
@@ -1237,10 +1237,13 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
      * @param activityInTask            activity in the same Task so that we can get the Task bounds
      *                                  if needed.
      * @param taskId                    parent Task of the new TaskFragment.
+     * @param pairedPrimaryContainer    the paired primary {@link TaskFragmentContainer}. When it is
+     *                                  set, the new container will be added right above it.
      */
     @GuardedBy("mLock")
     TaskFragmentContainer newContainer(@Nullable Activity pendingAppearedActivity,
-            @Nullable Intent pendingAppearedIntent, @NonNull Activity activityInTask, int taskId) {
+            @Nullable Intent pendingAppearedIntent, @NonNull Activity activityInTask, int taskId,
+            @Nullable TaskFragmentContainer pairedPrimaryContainer) {
         if (activityInTask == null) {
             throw new IllegalArgumentException("activityInTask must not be null,");
         }
@@ -1249,7 +1252,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
         }
         final TaskContainer taskContainer = mTaskContainers.get(taskId);
         final TaskFragmentContainer container = new TaskFragmentContainer(pendingAppearedActivity,
-                pendingAppearedIntent, taskContainer, this);
+                pendingAppearedIntent, taskContainer, this, pairedPrimaryContainer);
         return container;
     }
 
diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitPresenter.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitPresenter.java
index 5395fb2ef5ed1..47253d388f0dd 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitPresenter.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitPresenter.java
@@ -36,6 +36,7 @@ import android.util.Size;
 import android.view.View;
 import android.view.WindowInsets;
 import android.view.WindowMetrics;
+import android.window.TaskFragmentCreationParams;
 import android.window.WindowContainerTransaction;
 
 import androidx.annotation.GuardedBy;
@@ -307,10 +308,13 @@ class SplitPresenter extends JetpackTaskFragmentOrganizer {
         }
 
         final int taskId = primaryContainer.getTaskId();
-        final TaskFragmentContainer secondaryContainer = mController.newContainer(activityIntent,
-                launchingActivity, taskId);
-        final int windowingMode = mController.getTaskContainer(taskId)
-                .getWindowingModeForSplitTaskFragment(primaryRectBounds);
+        final TaskFragmentContainer secondaryContainer = mController.newContainer(
+                null /* pendingAppearedActivity */, activityIntent, launchingActivity, taskId,
+                // Pass in the primary container to make sure it is added right above the primary.
+                primaryContainer);
+        final TaskContainer taskContainer = mController.getTaskContainer(taskId);
+        final int windowingMode = taskContainer.getWindowingModeForSplitTaskFragment(
+                primaryRectBounds);
         mController.registerSplit(wct, primaryContainer, launchingActivity, secondaryContainer,
                 rule, splitAttributes);
         startActivityToSide(wct, primaryContainer.getTaskFragmentToken(), primaryRectBounds,
@@ -412,17 +416,18 @@ class SplitPresenter extends JetpackTaskFragmentOrganizer {
     }
 
     @Override
-    void createTaskFragment(@NonNull WindowContainerTransaction wct, @NonNull IBinder fragmentToken,
-            @NonNull IBinder ownerToken, @NonNull Rect bounds, @WindowingMode int windowingMode) {
-        final TaskFragmentContainer container = mController.getContainer(fragmentToken);
+    void createTaskFragment(@NonNull WindowContainerTransaction wct,
+            @NonNull TaskFragmentCreationParams fragmentOptions) {
+        final TaskFragmentContainer container = mController.getContainer(
+                fragmentOptions.getFragmentToken());
         if (container == null) {
             throw new IllegalStateException(
                     "Creating a task fragment that is not registered with controller.");
         }
 
-        container.setLastRequestedBounds(bounds);
-        container.setLastRequestedWindowingMode(windowingMode);
-        super.createTaskFragment(wct, fragmentToken, ownerToken, bounds, windowingMode);
+        container.setLastRequestedBounds(fragmentOptions.getInitialBounds());
+        container.setLastRequestedWindowingMode(fragmentOptions.getWindowingMode());
+        super.createTaskFragment(wct, fragmentOptions);
     }
 
     @Override
diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java
index e31792ad718f1..fcf0ac78af387 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java
@@ -118,10 +118,12 @@ class TaskFragmentContainer {
     /**
      * Creates a container with an existing activity that will be re-parented to it in a window
      * container transaction.
+     * @param pairedPrimaryContainer    when it is set, the new container will be add right above it
      */
     TaskFragmentContainer(@Nullable Activity pendingAppearedActivity,
             @Nullable Intent pendingAppearedIntent, @NonNull TaskContainer taskContainer,
-            @NonNull SplitController controller) {
+            @NonNull SplitController controller,
+            @Nullable TaskFragmentContainer pairedPrimaryContainer) {
         if ((pendingAppearedActivity == null && pendingAppearedIntent == null)
                 || (pendingAppearedActivity != null && pendingAppearedIntent != null)) {
             throw new IllegalArgumentException(
@@ -130,7 +132,16 @@ class TaskFragmentContainer {
         mController = controller;
         mToken = new Binder("TaskFragmentContainer");
         mTaskContainer = taskContainer;
-        taskContainer.mContainers.add(this);
+        if (pairedPrimaryContainer != null) {
+            if (pairedPrimaryContainer.getTaskContainer() != taskContainer) {
+                throw new IllegalArgumentException(
+                        "pairedPrimaryContainer must be in the same Task");
+            }
+            final int primaryIndex = taskContainer.mContainers.indexOf(pairedPrimaryContainer);
+            taskContainer.mContainers.add(primaryIndex + 1, this);
+        } else {
+            taskContainer.mContainers.add(this);
+        }
         if (pendingAppearedActivity != null) {
             addPendingAppearedActivity(pendingAppearedActivity);
         }
diff --git a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizerTest.java b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizerTest.java
index 31aa09c902b14..bbb454d31c388 100644
--- a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizerTest.java
+++ b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/JetpackTaskFragmentOrganizerTest.java
@@ -102,7 +102,7 @@ public class JetpackTaskFragmentOrganizerTest {
     public void testExpandTaskFragment() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                new Intent(), taskContainer, mSplitController);
+                new Intent(), taskContainer, mSplitController, null /* pairedPrimaryContainer */);
         final TaskFragmentInfo info = createMockInfo(container);
         mOrganizer.mFragmentInfos.put(container.getTaskFragmentToken(), info);
         container.setInfo(mTransaction, info);
diff --git a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java
index 221c7640ef0b5..6725dfdb94e81 100644
--- a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java
+++ b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java
@@ -169,7 +169,7 @@ public class SplitControllerTest {
         final TaskContainer taskContainer = createTestTaskContainer();
         // tf1 has no running activity so is not active.
         final TaskFragmentContainer tf1 = new TaskFragmentContainer(null /* activity */,
-                new Intent(), taskContainer, mSplitController);
+                new Intent(), taskContainer, mSplitController, null /* pairedPrimaryContainer */);
         // tf2 has running activity so is active.
         final TaskFragmentContainer tf2 = mock(TaskFragmentContainer.class);
         doReturn(1).when(tf2).getRunningActivityCount();
@@ -375,7 +375,7 @@ public class SplitControllerTest {
         final Intent intent = new Intent();
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                intent, taskContainer, mSplitController);
+                intent, taskContainer, mSplitController, null /* pairedPrimaryContainer */);
         final SplitController.ActivityStartMonitor monitor =
                 mSplitController.getActivityStartMonitor();
 
@@ -609,7 +609,7 @@ public class SplitControllerTest {
                 false /* isOnReparent */);
 
         assertFalse(result);
-        verify(mSplitController, never()).newContainer(any(), any(), any(), anyInt());
+        verify(mSplitController, never()).newContainer(any(), any(), any(), anyInt(), any());
     }
 
     @Test
@@ -771,7 +771,7 @@ public class SplitControllerTest {
                 false /* isOnReparent */);
 
         assertTrue(result);
-        verify(mSplitController, never()).newContainer(any(), any(), any(), anyInt());
+        verify(mSplitController, never()).newContainer(any(), any(), any(), anyInt(), any());
         verify(mSplitController, never()).registerSplit(any(), any(), any(), any(), any(), any());
     }
 
@@ -813,7 +813,7 @@ public class SplitControllerTest {
                 false /* isOnReparent */);
 
         assertTrue(result);
-        verify(mSplitController, never()).newContainer(any(), any(), any(), anyInt());
+        verify(mSplitController, never()).newContainer(any(), any(), any(), anyInt(), any());
         verify(mSplitController, never()).registerSplit(any(), any(), any(), any(), any(), any());
     }
 
diff --git a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskContainerTest.java b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskContainerTest.java
index 95328ce700e30..13e709271221b 100644
--- a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskContainerTest.java
+++ b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskContainerTest.java
@@ -122,7 +122,7 @@ public class TaskContainerTest {
         assertTrue(taskContainer.isEmpty());
 
         final TaskFragmentContainer tf = new TaskFragmentContainer(null /* activity */,
-                new Intent(), taskContainer, mController);
+                new Intent(), taskContainer, mController, null /* pairedPrimaryContainer */);
 
         assertFalse(taskContainer.isEmpty());
 
@@ -138,11 +138,11 @@ public class TaskContainerTest {
         assertNull(taskContainer.getTopTaskFragmentContainer());
 
         final TaskFragmentContainer tf0 = new TaskFragmentContainer(null /* activity */,
-                new Intent(), taskContainer, mController);
+                new Intent(), taskContainer, mController, null /* pairedPrimaryContainer */);
         assertEquals(tf0, taskContainer.getTopTaskFragmentContainer());
 
         final TaskFragmentContainer tf1 = new TaskFragmentContainer(null /* activity */,
-                new Intent(), taskContainer, mController);
+                new Intent(), taskContainer, mController, null /* pairedPrimaryContainer */);
         assertEquals(tf1, taskContainer.getTopTaskFragmentContainer());
     }
 
diff --git a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskFragmentContainerTest.java b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskFragmentContainerTest.java
index 99f56b4ceb172..5c3ba72e23619 100644
--- a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskFragmentContainerTest.java
+++ b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/TaskFragmentContainerTest.java
@@ -94,18 +94,21 @@ public class TaskFragmentContainerTest {
 
         // One of the activity and the intent must be non-null
         assertThrows(IllegalArgumentException.class,
-                () -> new TaskFragmentContainer(null, null, taskContainer, mController));
+                () -> new TaskFragmentContainer(null, null, taskContainer, mController,
+                        null /* pairedPrimaryContainer */));
 
         // One of the activity and the intent must be null.
         assertThrows(IllegalArgumentException.class,
-                () -> new TaskFragmentContainer(mActivity, mIntent, taskContainer, mController));
+                () -> new TaskFragmentContainer(mActivity, mIntent, taskContainer, mController,
+                        null /* pairedPrimaryContainer */));
     }
 
     @Test
     public void testFinish() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(mActivity,
-                null /* pendingAppearedIntent */, taskContainer, mController);
+                null /* pendingAppearedIntent */, taskContainer, mController,
+                null /* pairedPrimaryContainer */);
         doReturn(container).when(mController).getContainerWithActivity(mActivity);
 
         // Only remove the activity, but not clear the reference until appeared.
@@ -137,12 +140,14 @@ public class TaskFragmentContainerTest {
     public void testFinish_notFinishActivityThatIsReparenting() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container0 = new TaskFragmentContainer(mActivity,
-                null /* pendingAppearedIntent */, taskContainer, mController);
+                null /* pendingAppearedIntent */, taskContainer, mController,
+                null /* pairedPrimaryContainer */);
         final TaskFragmentInfo info = createMockTaskFragmentInfo(container0, mActivity);
         container0.setInfo(mTransaction, info);
         // Request to reparent the activity to a new TaskFragment.
         final TaskFragmentContainer container1 = new TaskFragmentContainer(mActivity,
-                null /* pendingAppearedIntent */, taskContainer, mController);
+                null /* pendingAppearedIntent */, taskContainer, mController,
+                null /* pairedPrimaryContainer */);
         doReturn(container1).when(mController).getContainerWithActivity(mActivity);
         final WindowContainerTransaction wct = new WindowContainerTransaction();
 
@@ -159,7 +164,8 @@ public class TaskFragmentContainerTest {
         final TaskContainer taskContainer = createTestTaskContainer();
         // Pending activity should be cleared when it has appeared on server side.
         final TaskFragmentContainer pendingActivityContainer = new TaskFragmentContainer(mActivity,
-                null /* pendingAppearedIntent */, taskContainer, mController);
+                null /* pendingAppearedIntent */, taskContainer, mController,
+                null /* pairedPrimaryContainer */);
 
         assertTrue(pendingActivityContainer.mPendingAppearedActivities.contains(
                 mActivity.getActivityToken()));
@@ -172,7 +178,8 @@ public class TaskFragmentContainerTest {
 
         // Pending intent should be cleared when the container becomes non-empty.
         final TaskFragmentContainer pendingIntentContainer = new TaskFragmentContainer(
-                null /* pendingAppearedActivity */, mIntent, taskContainer, mController);
+                null /* pendingAppearedActivity */, mIntent, taskContainer, mController,
+                null /* pairedPrimaryContainer */);
 
         assertEquals(mIntent, pendingIntentContainer.getPendingAppearedIntent());
 
@@ -187,7 +194,7 @@ public class TaskFragmentContainerTest {
     public void testIsWaitingActivityAppear() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
 
         assertTrue(container.isWaitingActivityAppear());
 
@@ -209,7 +216,7 @@ public class TaskFragmentContainerTest {
         doNothing().when(mController).onTaskFragmentAppearEmptyTimeout(any(), any());
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
 
         assertNull(container.mAppearEmptyTimeout);
 
@@ -249,7 +256,7 @@ public class TaskFragmentContainerTest {
     public void testCollectNonFinishingActivities() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         List<Activity> activities = container.collectNonFinishingActivities();
 
         assertTrue(activities.isEmpty());
@@ -277,7 +284,7 @@ public class TaskFragmentContainerTest {
     public void testAddPendingActivity() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         container.addPendingAppearedActivity(mActivity);
 
         assertEquals(1, container.collectNonFinishingActivities().size());
@@ -291,9 +298,9 @@ public class TaskFragmentContainerTest {
     public void testIsAbove() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container0 = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         final TaskFragmentContainer container1 = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
 
         assertTrue(container1.isAbove(container0));
         assertFalse(container0.isAbove(container1));
@@ -303,7 +310,7 @@ public class TaskFragmentContainerTest {
     public void testGetBottomMostActivity() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         container.addPendingAppearedActivity(mActivity);
 
         assertEquals(mActivity, container.getBottomMostActivity());
@@ -320,7 +327,7 @@ public class TaskFragmentContainerTest {
     public void testOnActivityDestroyed() {
         final TaskContainer taskContainer = createTestTaskContainer(mController);
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         container.addPendingAppearedActivity(mActivity);
         final List<IBinder> activities = new ArrayList<>();
         activities.add(mActivity.getActivityToken());
@@ -340,7 +347,7 @@ public class TaskFragmentContainerTest {
         // True if no info set.
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         spyOn(taskContainer);
         doReturn(true).when(taskContainer).isVisible();
 
@@ -403,7 +410,7 @@ public class TaskFragmentContainerTest {
     public void testHasAppearedActivity() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         container.addPendingAppearedActivity(mActivity);
 
         assertFalse(container.hasAppearedActivity(mActivity.getActivityToken()));
@@ -420,7 +427,7 @@ public class TaskFragmentContainerTest {
     public void testHasPendingAppearedActivity() {
         final TaskContainer taskContainer = createTestTaskContainer();
         final TaskFragmentContainer container = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         container.addPendingAppearedActivity(mActivity);
 
         assertTrue(container.hasPendingAppearedActivity(mActivity.getActivityToken()));
@@ -437,9 +444,9 @@ public class TaskFragmentContainerTest {
     public void testHasActivity() {
         final TaskContainer taskContainer = createTestTaskContainer(mController);
         final TaskFragmentContainer container1 = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
         final TaskFragmentContainer container2 = new TaskFragmentContainer(null /* activity */,
-                mIntent, taskContainer, mController);
+                mIntent, taskContainer, mController, null /* pairedPrimaryContainer */);
 
         // Activity is pending appeared on container2.
         container2.addPendingAppearedActivity(mActivity);
@@ -472,6 +479,27 @@ public class TaskFragmentContainerTest {
         assertTrue(container2.hasActivity(mActivity.getActivityToken()));
     }
 
+    @Test
+    public void testNewContainerWithPairedPrimaryContainer() {
+        final TaskContainer taskContainer = createTestTaskContainer();
+        final TaskFragmentContainer tf0 = new TaskFragmentContainer(
+                null /* pendingAppearedActivity */, new Intent(), taskContainer, mController,
+                null /* pairedPrimaryTaskFragment */);
+        final TaskFragmentContainer tf1 = new TaskFragmentContainer(
+                null /* pendingAppearedActivity */, new Intent(), taskContainer, mController,
+                null /* pairedPrimaryTaskFragment */);
+        taskContainer.mContainers.add(tf0);
+        taskContainer.mContainers.add(tf1);
+
+        // When tf2 is created with using tf0 as pairedPrimaryContainer, tf2 should be inserted
+        // right above tf0.
+        final TaskFragmentContainer tf2 = new TaskFragmentContainer(
+                null /* pendingAppearedActivity */, new Intent(), taskContainer, mController, tf0);
+        assertEquals(0, taskContainer.indexOf(tf0));
+        assertEquals(1, taskContainer.indexOf(tf2));
+        assertEquals(2, taskContainer.indexOf(tf1));
+    }
+
     /** Creates a mock activity in the organizer process. */
     private Activity createMockActivity() {
         final Activity activity = mock(Activity.class);
diff --git a/services/core/java/com/android/server/wm/WindowOrganizerController.java b/services/core/java/com/android/server/wm/WindowOrganizerController.java
index dc1d50c435b91..cd777092d4387 100644
--- a/services/core/java/com/android/server/wm/WindowOrganizerController.java
+++ b/services/core/java/com/android/server/wm/WindowOrganizerController.java
@@ -1891,7 +1891,18 @@ class WindowOrganizerController extends IWindowOrganizerController.Stub
         // actions.
         taskFragment.setTaskFragmentOrganizer(creationParams.getOrganizer(),
                 ownerActivity.getUid(), ownerActivity.info.processName);
-        ownerTask.addChild(taskFragment, POSITION_TOP);
+        final int position;
+        if (creationParams.getPairedPrimaryFragmentToken() != null) {
+            // When there is a paired primary TaskFragment, we want to place the new TaskFragment
+            // right above the paired one to make sure there is no other window in between.
+            final TaskFragment pairedPrimaryTaskFragment = getTaskFragment(
+                    creationParams.getPairedPrimaryFragmentToken());
+            final int pairedPosition = ownerTask.mChildren.indexOf(pairedPrimaryTaskFragment);
+            position = pairedPosition != -1 ? pairedPosition + 1 : POSITION_TOP;
+        } else {
+            position = POSITION_TOP;
+        }
+        ownerTask.addChild(taskFragment, position);
         taskFragment.setWindowingMode(creationParams.getWindowingMode());
         taskFragment.setBounds(creationParams.getInitialBounds());
         mLaunchTaskFragments.put(creationParams.getFragmentToken(), taskFragment);
diff --git a/services/tests/wmtests/src/com/android/server/wm/TaskFragmentOrganizerControllerTest.java b/services/tests/wmtests/src/com/android/server/wm/TaskFragmentOrganizerControllerTest.java
index 2b493145f854b..6cb3450ee4701 100644
--- a/services/tests/wmtests/src/com/android/server/wm/TaskFragmentOrganizerControllerTest.java
+++ b/services/tests/wmtests/src/com/android/server/wm/TaskFragmentOrganizerControllerTest.java
@@ -552,10 +552,9 @@ public class TaskFragmentOrganizerControllerTest extends WindowTestsBase {
     @Test
     public void testApplyTransaction_enforceHierarchyChange_createTaskFragment() {
         final ActivityRecord ownerActivity = createActivityRecord(mDisplayContent);
-        final IBinder fragmentToken = new Binder();
 
         // Allow organizer to create TaskFragment and start/reparent activity to TaskFragment.
-        createTaskFragmentFromOrganizer(mTransaction, ownerActivity, fragmentToken);
+        createTaskFragmentFromOrganizer(mTransaction, ownerActivity, mFragmentToken);
         mTransaction.startActivityInTaskFragment(
                 mFragmentToken, null /* callerToken */, new Intent(), null /* activityOptions */);
         mTransaction.reparentActivityToTaskFragment(mFragmentToken, mock(IBinder.class));
@@ -564,7 +563,8 @@ public class TaskFragmentOrganizerControllerTest extends WindowTestsBase {
         assertApplyTransactionAllowed(mTransaction);
 
         // Successfully created a TaskFragment.
-        final TaskFragment taskFragment = mWindowOrganizerController.getTaskFragment(fragmentToken);
+        final TaskFragment taskFragment = mWindowOrganizerController.getTaskFragment(
+                mFragmentToken);
         assertNotNull(taskFragment);
         assertEquals(ownerActivity.getTask(), taskFragment.getTask());
     }
@@ -702,6 +702,40 @@ public class TaskFragmentOrganizerControllerTest extends WindowTestsBase {
         assertNotNull(mWindowOrganizerController.getTaskFragment(fragmentToken));
     }
 
+    @Test
+    public void testApplyTransaction_createTaskFragment_withPairedPrimaryFragmentToken() {
+        final Task task = createTask(mDisplayContent);
+        mTaskFragment = new TaskFragmentBuilder(mAtm)
+                .setParentTask(task)
+                .setFragmentToken(mFragmentToken)
+                .createActivityCount(1)
+                .build();
+        mWindowOrganizerController.mLaunchTaskFragments.put(mFragmentToken, mTaskFragment);
+        final ActivityRecord activityOnTop = createActivityRecord(task);
+        final int uid = Binder.getCallingUid();
+        activityOnTop.info.applicationInfo.uid = uid;
+        activityOnTop.getTask().effectiveUid = uid;
+        final IBinder fragmentToken1 = new Binder();
+        final TaskFragmentCreationParams params = new TaskFragmentCreationParams.Builder(
+                mOrganizerToken, fragmentToken1, activityOnTop.token)
+                .setPairedPrimaryFragmentToken(mFragmentToken)
+                .build();
+        mTransaction.setTaskFragmentOrganizer(mIOrganizer);
+        mTransaction.createTaskFragment(params);
+        assertApplyTransactionAllowed(mTransaction);
+
+        // Successfully created a TaskFragment.
+        final TaskFragment taskFragment = mWindowOrganizerController.getTaskFragment(
+                fragmentToken1);
+        assertNotNull(taskFragment);
+        // The new TaskFragment should be positioned right above the paired TaskFragment.
+        assertEquals(task.mChildren.indexOf(mTaskFragment) + 1,
+                task.mChildren.indexOf(taskFragment));
+        // The top activity should remain on top.
+        assertEquals(task.mChildren.indexOf(taskFragment) + 1,
+                task.mChildren.indexOf(activityOnTop));
+    }
+
     @Test
     public void testApplyTransaction_enforceHierarchyChange_reparentChildren() {
         doReturn(true).when(mTaskFragment).isAttached();