Watch this video. It is hard to navigate GA5 at first, it doesn’t have things where you think they would be. Go to the Kit, as I show in the video, and tag the drop down menu. Here you will find what you are looking for, a listing of all your Kits and add on sound banks. Hm, it seems I can’t load an apple movie here…
Try this: Finding purchased/add-on sound banks in Steinberg GA5 - YouTube