How to dismiss the bottom sheet with in page child transition

[lucasjinreal]

 return Navigator(
      onGenerateRoute: (_) => MaterialPageRoute(builder: (context) {
        return CupertinoPageScaffold(
          navigationBar: appBar(context),

I have a view like this, which using demo code, push child page with inside CupertinoScaffold.

As you can see, I can not call Navigator.pop inside CuperitnoPageScaffold to dismiss the whole bottom sheet page. since it just pop up CupertinoPageScaffold itself, but not the root Navigator.

What should I do/