How to check if the current destination is top level in Jetpack Compose type-safe navigation?

I have a multibackstack navigation graph where each starting node for the bottom navigation is top level.

How can I check if I am currently in the top level destination in order to adjust the display of a UI element for example?

The following code sample does not solve the problem:

val isTopLevel = navController.previousBackStackEntry == null

Between top-level destinations, I navigate as follows:

navController.navigate(destination.route) {
    popUpTo(navController.graph.findStartDestination().id) {
        saveState = true
        inclusive = true
    }
    launchSingleTop = true
    restoreState = true
}

If you know top level NavDestinations that are not NavGraphs you can create a list and check if current destination is these top level list.

For instance for this navigation

navigation<BottomNavigationRoute.HomeGraph>(
    startDestination = BottomNavigationRoute.HomeRoute1
) {
    composable<BottomNavigationRoute.HomeRoute1> { from: NavBackStackEntry ->
        Screen(
            text = "Home Screen1",
            navController = nestedNavController,
            onClick = {
                onBottomScreenClick(BottomNavigationRoute.HomeRoute2, from)
            }
        )
    }

    composable<BottomNavigationRoute.HomeRoute2> { from: NavBackStackEntry ->
        Screen(
            text = "Home Screen2",
            navController = nestedNavController,
            onClick = {
                onBottomScreenClick(BottomNavigationRoute.HomeRoute3, from)
            }
        )
    }

    composable<BottomNavigationRoute.HomeRoute3> { from: NavBackStackEntry ->
        Screen(
            text = "Home Screen3",
            navController = nestedNavController
        )
    }
}

HomeRoute1 is NavDestination while HomeGraph is NavGraph.

If you wish to do this dynamically you can check whether it's a NavGraph or NavDestination first.

    val nestedNavController = rememberNavController()

    val navBackStackEntry: NavBackStackEntry? by nestedNavController.currentBackStackEntryAsState()
    val currentDestination = navBackStackEntry?.destination


    val topLevelDestinations = remember {
        mutableStateListOf<NavDestination>()
    }

    currentDestination?.hierarchy?.let {
        if (topLevelDestinations.isEmpty()) {
            nestedNavController.graph.nodes.forEach { id, navDestination: NavDestination ->
                if (navDestination is NavGraph) {
                    topLevelDestinations.add(navDestination[navDestination.startDestinationId])
                } else {
                    topLevelDestinations.add(navDestination)
                }
            }
        }
    }

val topLevelDestination =
    topLevelDestinations.isNotEmpty() && topLevelDestinations.contains(currentDestination)