Final activity_main.xml

activity_main.xml

<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.view.activity.MainActivity">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/navHostFragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/toolbar"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_graph" />

    <com.google.android.material.bottomappbar.BottomAppBar
        android:id="@+id/bottomAppBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        app:fabAlignmentMode="center"
        app:fabCradleRoundedCornerRadius="20dp"
        app:fabCradleMargin="8dp"
        app:contentInsetStart="0dp"
        app:contentInsetStartWithNavigation="0dp"
        app:hideOnScroll="true">

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/bottomNav"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@android:color/transparent"
            android:outlineAmbientShadowColor="@android:color/transparent"
            android:outlineSpotShadowColor="@android:color/transparent"
            app:menu="@menu/bottom_nav_menu" />

    </com.google.android.material.bottomappbar.BottomAppBar>

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/phoneSearchFab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_search"
        android:contentDescription="@string/search_phone"
        app:layout_anchor="@id/bottomAppBar"
        app:backgroundTint="@color/colorPrimary"
        app:tint="@color/white"
        app:elevation="4dp" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>