How to implement searchView widget in android Studio through Recycleview?

<androidx.appcompat.widget.SearchView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/search_bar"
                android:layout_margin="5dp"
                android:background="@color/white"
                app:queryHint="@string/hint_search"
                app:iconifiedByDefault="false"/>

public class CollectExpandableListAdapter extends BaseExpandableListAdapter implements Filterable {
//......Your all code goes here..
}

public class CollectExpandableListAdapter extends BaseExpandableListAdapter implements Filterable {
    private static final String TAG = "tag";
    private final Context _context;
    private List<Parent> _listDataHeader; // header title
    private List<Parent> originalList;
    private final HashMap<Parent, List<Child>> _listDataChild;

//...Rest code...
}

 SearchView searchView;

// initialize the variable
       searchView = view.findViewById(R.id.search_bar);

searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                Log.d("newText1",query);
                return false;
            }
            @Override
            public boolean onQueryTextChange(String newText) {
                if ( TextUtils.isEmpty ( newText ) ) {
                    expListAdapter.getFilter().filter("");
                } else {
                    expListAdapter.getFilter().filter(newText.toString());
                }
                return true;
            }
        });

 public Filter getFilter() {
        return new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence constraint) {
                final FilterResults filterResults= new FilterResults();
                final List<Parent> results = new ArrayList<Parent>();
                if (originalList == null)
                    originalList = _listDataHeader;
                if (constraint != null) {
                    assert originalList != null;
                    if (originalList.size() > 0) {
                        for (final Parent item : originalList) {
                            if (item.getPostcode().toLowerCase().contains(constraint.toString()) ||
                                    (item.getAddress().toLowerCase().contains(constraint.toString())) ||
                                        (item.getState().toLowerCase().contains(constraint.toString())))
                            {
                                results.add(item);
                            }
                        }
                    }
                    filterResults.values = results;
                }
                return filterResults;
            }

            @Override
            protected void publishResults(CharSequence constraint, FilterResults results) {
                _listDataHeader = (ArrayList<Parent>) results.values;
                notifyDataSetChanged();

            }
        };