Undefined for firebase subscribe

Question

I need to return array of items to display it on HomePage

I tried to modify the code, but nothing works. I feel like I need a slight change for my code

getItems(segmentType): any {
  return this.db.collection('items', ref => ref.where('type', '==', 
  segmentType)).valueChanges();
}

getItemsBySearchQuery(segmentType, queryText): any[] {
  this.getItems(segmentType).subscribe(items => {

    this.itemsContainer = items;

    this.filteredItems = this.itemsContainer.filter((v) => {
      if (v.title && queryText) {
        if (v.title.toLowerCase().indexOf(queryText.toLowerCase()) > -1) {
          return true;
        }
        return false;
      }
    });
  });

  //TODO: THIS IS STILL UNDEFINED
  return this.filteredItems;
}

Ion-List with filtered elements, but I have "undefined", because code returns the array too early