samples/VirtualDeviceManager/host/res/layout/fragment_input_navigation.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/nav_touchpad_fragment_container"
        android:name="com.example.android.vdmdemo.common.NavTouchpadFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/dpad_fragment_container"
        android:name="com.example.android.vdmdemo.common.DpadFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/rotary_fragment_container"
        android:name="com.example.android.vdmdemo.common.RotaryFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1" />

</LinearLayout>