Matt J. - for your reference, fixed it. I've had to add each filter as a collection item, and then the same in the list where all the things we're trying to filter are (The doctors in this case)
Alright I won't waste any more of your time! I'll jump in and reconnect the component, see if that works. If not, I'll be back. Thanks so much mate, you're a legend. Really appreciate it Matt J.