All three elements should be frame layouts, but the root element should be a relative layout. Also notice, in relative layout elements are positioned as layers from the lowest to the higest. (from top to bottom of xml file) The first element - is the lowest, next is on top of first, etc.
Your layout should look like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="@+id/container_square_with_rounded_corners"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"/>
<FrameLayout
android:id="@+id/container_circle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentBottom="true"/>
<FrameLayout
android:id="@+id/container_square"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"/>
</RelativeLayout>