Sending data from nested fragments to parent fragment

The best way is use an interface:

1. Declare an interface in the nest fragment

   // Container Activity or Fragment must implement this interface
   public interface OnPlayerSelectionSetListener
   {
       public void onPlayerSelectionSet(List<Player> players_ist);
   }
   

2. Attach the interface to parent fragment

   // In the child fragment.
   public void onAttachToParentFragment(Fragment fragment)
   {
       try
       {
           mOnPlayerSelectionSetListener = (OnPlayerSelectionSetListener)fragment;
   
       }
       catch (ClassCastException e)
       {
             throw new ClassCastException(
                 fragment.toString() + " must implement OnPlayerSelectionSetListener");
       }
   }
   
   
   @Override
   public void onCreate(Bundle savedInstanceState)
   {
       Log.i(TAG, "onCreate");
       super.onCreate(savedInstanceState);
   
       onAttachToParentFragment(getParentFragment());
   
       // ...
   }
   

3. Call the listener on button click.

   // In the child fragment.
   @Override
   public void onClick(View v)
   {
       switch (v.getId())
       {
           case R.id.tv_submit:
               if (mOnPlayerSelectionSetListener != null)
               {                
                    mOnPlayerSelectionSetListener.onPlayerSelectionSet(selectedPlayers);
               }
               break;
           }
       }
   

4. Have your parent fragment implement the interface.

    public class Fragment_Parent extends Fragment implements Nested_Fragment.OnPlayerSelectionSetListener
    {
         // ...
         @Override
         public void onPlayerSelectionSet(final List<Player> players_list)
         {
              FragmentManager fragmentManager = getChildFragmentManager();
              SomeOtherNestFrag someOtherNestFrag = (SomeOtherNestFrag)fragmentManager.findFragmentByTag("Some fragment tag");
              //Tag of your fragment which you should use when you add
   
              if(someOtherNestFrag != null)
              {
                   // your some other frag need to provide some data back based on views.
                   SomeData somedata = someOtherNestFrag.getSomeData();
                   // it can be a string, or int, or some custom java object.
              }
         }
    }
   

Add Tag when you do fragment transaction so you can look it up afterward to call its method. FragmentTransaction

This is the proper way to handle communication between fragment and nest fragment, it’s almost the same for activity and fragment.
http://developer.android.com/guide/components/fragments.html#EventCallbacks

There is actually another official way, it’s using activity result, but this one is good enough and common.