Is there any new way to implement multiple back stacks automatically in android studio? - android-fragments

Question

I am new in android studio and I hope that the question is not too trivial. I have been searching for several days to find an official solution for multiple back stacks in java script. Take a simple project I have, a bottom navigation with two items, item_home and item_users. like below:
My bottom navigation bar
This is the activity_main.xml code:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<fragment
android:id="#+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:defaultNavHost="true"
/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottomNavigationView"
android:layout_width="match_parent"
android:layout_height="50dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:menu="#menu/bottom_nav_menu"/>
</androidx.constraintlayout.widget.ConstraintLayout>
And I have two navigation graph for home and users items, selected programicaly in the MainActivity.java. Here is the MainActivity.java :
package com.example.testnavigationgraph;
import static androidx.navigation.fragment.NavHostFragment.findNavController;
import static androidx.navigation.ui.NavigationUI.setupActionBarWithNavController;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentContainerView;
import androidx.fragment.app.FragmentManager;
import androidx.navigation.NavController;
import androidx.navigation.NavOptions;
import androidx.navigation.Navigation;
import androidx.navigation.fragment.NavHostFragment;
import androidx.navigation.ui.NavigationUI;
import android.app.Activity;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import com.google.android.material.bottomnavigation.BottomNavigationView;
import com.google.android.material.navigation.NavigationView;
public class MainActivity extends AppCompatActivity {
private Bundle bundle;
private Fragment fragment;
FragmentManager fragmentManager;
BottomNavigationView bottomNavigationView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bottomNavigationView = findViewById(R.id.bottomNavigationView);
bottomNavigationView.setOnNavigationItemSelectedListener(bOnClickListener);
bottomNavigationView.setSelectedItemId(R.id.item_home);
}
///////////////////Bottom Navigation//////////////////////////////
private BottomNavigationView.OnNavigationItemSelectedListener
bOnClickListener =new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.item_home:
Navigation.findNavController(MainActivity.this,R.id.nav_host_fragment).setGraph(R.navigation.nav_graph);
return true;
case R.id.item_users:
Navigation.findNavController(MainActivity.this,R.id.nav_host_fragment).setGraph(R.navigation.nav_graph2);
return true;
}
return false;
}
};
}
Please make a fast, simple solution for this controversial and widely used issue in java script.