BottomNavigationView有其自己的方法，用于通过setOnItemReselectedListener()（或者，当使用早期版本的材质设计库时，使用现在不建议使用的setOnNavigationItemReselectedListener()）处理重新选择。
bottomNavigationView.setupWithNavController没有设置这个监听器（因为没有Material规范来明确说明重新选择一个选项卡应该做什么），所以你需要自己设置它：

val bottomNavigationView = findViewById<BottomNavigationView>(R.id.bottom_nav)
bottomNavigationView.setupWithNavController(navController)

// Add your own reselected listener
bottomNavigationView.setOnItemReselectedListener { item ->
    // Pop everything up to the reselected item
    val reselectedDestinationId = item.itemId
    navController.popBackStack(reselectedDestinationId, inclusive = false)
}

这个被接受的答案让我朝着正确的方向开始了。然而，随着Android导航库2.4.0支持的多个backstack的增加，这是最终对我有效的：

val currentRootFragment = supportFragmentManager.findFragmentById(R.id.main_fragment)
val navHost = currentRootFragment as? NavHostFragment
val selectedMenuItemNavGraph = navHost?.navController?.graph?.findNode(menuItem.itemId) as? NavGraph?
selectedMenuItemNavGraph?.let { menuGraph ->
             navHost?.navController?.popBackStack(menuGraph.startDestinationId, false)
}

有两种方法可以拯救我们...
1.在选定项目后更新选择（具有反向堆栈的项目，使用最新版本-2.4.2，当顶部目标中存在反向堆栈时，选择该项目不会首先选择该项目）。
NavigationBarView.setOnItemSelectedListener {}
1.等待第二次单击并执行向后堆栈的弹出。
NavigationBarView.setOnItemReselectedListener {}
最终代码是，

val navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment?
    val navController = navHostFragment?.navController

    mainBinding?.bottomNavigation?.apply {
        navController?.let { navController ->
            NavigationUI.setupWithNavController(
                this,
                navController
            )
            setOnItemSelectedListener { item ->
                NavigationUI.onNavDestinationSelected(item, navController)
                true
            }
            setOnItemReselectedListener {
                navController.popBackStack(destinationId = it.itemId, inclusive = false)
            }
        }

}
希望这会有帮助。

此解决方案由Callie's和ianhanniballake's解决方案组成。
行为是

1. Home -> Detail Page A -> Detail Page B，然后按下Home button-〉Home
2. Home -> Detail Page A -> Detail Page B，然后导航至Profile，然后返回Home将显示Detail Page B，然后再次按下Home将触发1行为（因此将返回Home屏幕）。

// navView = id of BottomNavigationView

navController = findNavController(R.id.nav_host_container)
// where nav_host_container is the id of the fragment which is your default Nav host. 

binding.navView.setOnItemReselectedListener { menuItem ->              
   val selectedMenuItemNavGraph = 
       navController.graph.findNode(menuItem.itemId) as NavGraph              

   selectedMenuItemNavGraph.let { menuGraph ->           
       navController.popBackStack(menuGraph.startDestinationId, false)              
   }          
}

使用您自己的setupWithNavController2，而不是androidx.navigation.ui.BottomNavigationViewKt中的setupWithNavController
例如：
在导航之前添加了已选定项目的检查：

if (navController.popBackStack(item.itemId, false)) {
        return true
    }

参见onNavDestinationSelected的注解，setupWithNavController2的完整代码：

fun BottomNavigationView.setupWithNavController2(navController: NavController) {
    val bottomNavigationView = this
    bottomNavigationView.setOnItemSelectedListener { item ->
        onNavDestinationSelected(item, navController)
    }
    val weakReference = WeakReference(bottomNavigationView)
    navController.addOnDestinationChangedListener(
        object : NavController.OnDestinationChangedListener {
            override fun onDestinationChanged(
                controller: NavController,
                destination: NavDestination,
                arguments: Bundle?
            ) {
                val view = weakReference.get()
                if (view == null) {
                    navController.removeOnDestinationChangedListener(this)
                    return
                }
                val menu = view.menu
                var i = 0
                val size = menu.size()
                while (i < size) {
                    val item = menu.getItem(i)
                    if (matchDestination(destination, item.itemId)) {
                        item.isChecked = true
                    }
                    i++
                }
            }
        })

    // Add your own reselected listener
    bottomNavigationView.setOnItemReselectedListener { item ->
        // Pop everything up to the reselected item
        val reselectedDestinationId = item.itemId
        navController.popBackStack(reselectedDestinationId, false)
    }
}

fun onNavDestinationSelected(
    item: MenuItem,
    navController: NavController
): Boolean {
    val builder = NavOptions.Builder()
        .setLaunchSingleTop(true)
    if (navController.currentDestination?.parent?.findNode(item.itemId) is ActivityNavigator.Destination) {
        builder.setEnterAnim(R.anim.nav_default_enter_anim)
            .setExitAnim(R.anim.nav_default_exit_anim)
            .setPopEnterAnim(R.anim.nav_default_pop_enter_anim)
            .setPopExitAnim(R.anim.nav_default_pop_exit_anim)
    } else {
        builder.setEnterAnim(R.animator.nav_default_enter_anim)
            .setExitAnim(R.animator.nav_default_exit_anim)
            .setPopEnterAnim(R.animator.nav_default_pop_enter_anim)
            .setPopExitAnim(R.animator.nav_default_pop_exit_anim)
    }
    if (item.order and Menu.CATEGORY_SECONDARY == 0) {
        val findStartDestination = findStartDestination(navController.graph)
        if (findStartDestination != null) {
            builder.setPopUpTo(findStartDestination.id, false)
        }
    }
    val options = builder.build()
    //region The code was added to avoid adding already exist item
    if (navController.popBackStack(item.itemId, false)) {
        return true
    }
    //endregion
    return try {
        // TODO provide proper API instead of using Exceptions as Control-Flow.
        navController.navigate(item.itemId, null, options)
        true
    } catch (e: IllegalArgumentException) {
        false
    }
}

fun findStartDestination(graph: NavGraph): NavDestination? {
    var startDestination: NavDestination? = graph
    while (startDestination is NavGraph) {
        val parent = startDestination
        startDestination = parent.findNode(parent.startDestination)
    }
    return startDestination
}

fun matchDestination(
    destination: NavDestination,
    @IdRes destId: Int
): Boolean {
    var currentDestination: NavDestination? = destination
    while (currentDestination?.id != destId && currentDestination?.parent != null) {
        currentDestination = currentDestination.parent
    }
    return currentDestination?.id == destId
}

你必须显示底部导航栏只为R.id.titleScreen, R.id.leaderboard, R.id.register片段，对于其他人，它应该是隐藏的，他们应该只有工具栏与后退按钮