如果您的代码遵循单活动设计模式，那么下面的解决方案适合您。
1.在父Activity内创建一个方法以隐藏/显示bottomNavigationView。
1.创建一个BaseFragment类（通过扩展此BaseFragment类创建片段）
1.在BaseFragment中创建一个变量以保存bottomNavigationViewVisibility（隐藏/显示）
1.在BaseFragment的onActivityCreated方法中，通过调用我们在步骤1中创建的方法，获取活动引用并设置bottomNavigationViewVisibility。
1.在您创建的每个片段中，只需设置bottomNavigationViewVisibility变量。
示例：在parentActivity布局中，文件添加bottomNavigationView

<com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/main_bottom_navigation_view"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?android:attr/windowBackground"
            app:labelVisibilityMode="labeled"
            app:menu="@menu/main_nav" />

步骤1：在父活动中，创建一个方法来更改可见性。

fun setBottomNavigationVisibility(visibility: Int) {
        // get the reference of the bottomNavigationView and set the visibility.
        activityMainBinding.mainBottomNavigationView.visibility = visibility
    }

步骤2、3和4：

abstract class BaseFragment : Fragment() {
    
        protected open var bottomNavigationViewVisibility = View.VISIBLE
    
        override fun onActivityCreated(savedInstanceState: Bundle?) {
            super.onActivityCreated(savedInstanceState)
            // get the reference of the parent activity and call the setBottomNavigationVisibility method.
            if (activity is MainActivity) {
               var  mainActivity = activity as MainActivity
                mainActivity.setBottomNavigationVisibility(bottomNavigationViewVisibility)
            }
        }
 override fun onResume() {
        super.onResume()
        if (activity is MainActivity) {
            mainActivity.setBottomNavigationVisibility(bottomNavigationViewVisibility)
        }
    }
    }

第五步：

class SampleFragment1 : BaseFragment() {

    // set the visibility here, it takes care of setting the bottomNavigationView.
    override var navigationVisibility = View.VISIBLE
    
   // override var navigationVisibility = View.GONE

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_sampleFragment1, container, false)
    }
}