AnchoredFab.xml

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="top"
        android:src="@drawable/ic_add_black_24dp"
        app:fabSize="normal"
        app:layout_anchor="@id/navigation"
        app:layout_anchorGravity="top|end"
        app:layout_behavior="com.mypackage.BottomNavigationFABBehavior"
        app:useCompatPadding="true"/>