Isolate part of the app in it's own sandbox

[diabloproject]

As I never worked with gamedev, I may think in completely invalid way, if someone has a "proper" solution to my problem, please tell me.
The game that I'm trying to make has a lot of (nested) menus that overlay or replace each other in some way. I never worked on games before, so I've chosen the easiest to me method: Write everything in code except for assets (which is why I use bevy in the first place). Along the ride, I decided that the easiest way to do nested menus and various gameplay modes is to do something that emacs and vim like to do: Modes.
In theory, I should be able to make something like this:

trait MajorMode {
    fn before_enter(&mut self) {}
    fn after_enter(&mut self) {}
    
    fn before_leave(&mut self) {}
    fn after_leave(&mut self) {}
    fn setup(&mut self);
}

Where all the methods will additionally receive something like commands, but effectively on a separate layer, and in a way that cannot affect rest of the application.
But then i stumbled on a problem: How to isolate the commands to make it seem from the perspective of a mode that nothing, but the mode's components and entities exist in the current application?
So, the question is: How can I effectively create an isolate in bevy's ECS & rendering system so i can show to the mode only things that it itself created?