Function rememberNavController 

pub fn rememberNavController<R: Clone + PartialEq + 'static>(
    start: R,
) -> NavController<R>

A NavController whose back stack starts at start — Android’s rememberNavController() plus NavHost(startDestination).

The back stack lives in the nearest view model store, so a NavHost nested in a screen keeps its back stack while another screen covers that screen.