Android Navigation multiple start destinations. Java version based on Sam Clarke's workaround https://www.samclarke.com/android-navigation-component-multiple-start-destinations/

MultiStartNavigationUI.java

import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.graphics.drawable.DrawerArrowDrawable;
import android.text.TextUtils;
import android.view.Gravity;

import java.util.List;

import androidx.navigation.NavController;
import androidx.navigation.NavDestination;

public class MultiStartNavigationUI {
  
    public MultiStartNavigationUI() {
    }

    public static void setupActionBarWithNavController(@NonNull AppCompatActivity activity,
                                                       @NonNull NavController navController,
                                                       @NonNull List<Integer> startDestinations,
                                                       @Nullable DrawerLayout drawerLayout) {
        navController.addOnNavigatedListener(new ActionBarOnNavigatedListener(
                activity, startDestinations, drawerLayout));
    }

    public static boolean navigateUp(@Nullable DrawerLayout drawerLayout,
                                     @NonNull NavController navController,
                                     @NonNull List<Integer> startDestinations) {
        if (drawerLayout != null && startDestinations.contains(navController.getCurrentDestination().getId())) {
            drawerLayout.openDrawer(Gravity.START);
            return true;
        } else {
            return navController.navigateUp();
        }
    }

    public static boolean onBackPressed(@NonNull AppCompatActivity activity,
                                        @NonNull NavController navController,
                                        @NonNull List<Integer> startDestinations) {
        if (startDestinations.contains(navController.getCurrentDestination().getId())) {
            ActivityCompat.finishAfterTransition(activity);
            return true;
        }
        return false;
    }

    private static class ActionBarOnNavigatedListener implements NavController.OnNavigatedListener {
        private final AppCompatActivity mActivity;
        @Nullable
        private final DrawerLayout mDrawerLayout;
        private DrawerArrowDrawable mArrowDrawable;
        private ValueAnimator mAnimator;
        private List<Integer> mStartDestinations;

        ActionBarOnNavigatedListener(@NonNull AppCompatActivity activity,
                                     @NonNull List<Integer> startDestinations,
                                     @Nullable DrawerLayout drawerLayout) {
            mActivity = activity;
            mDrawerLayout = drawerLayout;
            mStartDestinations= startDestinations;
        }

        @Override
        public void onNavigated(@NonNull NavController controller,
                                @NonNull NavDestination destination) {
            ActionBar actionBar = mActivity.getSupportActionBar();
            CharSequence title = destination.getLabel();
            if (!TextUtils.isEmpty(title)) {
                actionBar.setTitle(title);
            }
            boolean isStartDestination = mStartDestinations.contains(destination.getId());
            actionBar.setDisplayHomeAsUpEnabled(mDrawerLayout != null || !isStartDestination);
            setActionBarUpIndicator(mDrawerLayout != null && isStartDestination);
        }

        void setActionBarUpIndicator(boolean showAsDrawerIndicator) {
            ActionBarDrawerToggle.Delegate delegate = mActivity.getDrawerToggleDelegate();
            boolean animate = true;
            if (mArrowDrawable == null) {
                mArrowDrawable = new DrawerArrowDrawable(
                        delegate.getActionBarThemedContext());
                delegate.setActionBarUpIndicator(mArrowDrawable, 0);
                // We're setting the initial state, so skip the animation
                animate = false;
            }
            float endValue = showAsDrawerIndicator ? 0f : 1f;
            if (animate) {
                float startValue = mArrowDrawable.getProgress();
                if (mAnimator != null) {
                    mAnimator.cancel();
                }
                mAnimator = ObjectAnimator.ofFloat(mArrowDrawable, "progress",
                        startValue, endValue);
                mAnimator.start();
            } else {
                mArrowDrawable.setProgress(endValue);
            }
        }
    }
}