Manage toolbar's navigation and back button from fragment in android

Add a toolbar to your xml

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Fragment title"/>

</android.support.v7.widget.Toolbar>

Then inside your onCreateView method in the Fragment:

Toolbar toolbar = view.findViewById(R.id.toolbar);
toolbar.setNavigationIcon(R.drawable.ic_back_button);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
         getActivity().onBackPressed();
    }
});

You have to manage your back button pressed action on your main Activity because your main Activity is container for your fragment.

First, add your all fragment to transaction.addToBackStack(null) and now navigation back button call will be going on main activity. I hope following code will help you...

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
        onBackPressed();
        }
    return super.onOptionsItemSelected(item);
}

you can also use

Fragment fragment =fragmentManager.findFragmentByTag(Constant.TAG); 
if(fragment!=null) {          
      FragmentTransaction transaction = fragmentManager.beginTransaction();
      transaction.remove(fragment).commit();
}

And to change the title according to fragment name from fragment you can use the following code:

activity.getSupportActionBar().setTitle("Keyword Report Detail");