How to pop 2 screen at once in flutter

I have not created any routes to navigate between screens. I use Navigator to navigate:

Navigator.push(context, MaterialPageRoute(builder: (context) => HomePage()));

what I have done is navigate to four screens from homePage to success screen:

HomePage => CreatePostScreen => CreateImagePost => SuccessfulScreen

when I reach to successfulscreen I would like to pop two screens and get back to CreatePostScreen.I do not want to write Navigator.pop(context) two times.

I tried to use this, but it will come up with a black screen:

Navigator.popUntil(context, (route) => route is CreatePostScreen);

but this is not working. I would like to learn how flutter handles widget navigation not by route names and solution to this.

I know something about how navigator class handles with route name but I would like to know how to solve it if I push widgets and its working.