Adding a 2nd and 3rd exterior camera

Dear Sirs, We currently only have a Ring Doorbell camera. I am looking to add a 2nd and 3rd exterior camera to my system - which I can see is simple enough. But what I would like to do is for the 2nd and 3rd cameras only to be visible to myself and not the 1 other who shares the front door camera. The area the 2 external cameras will view is not of concern to my lodger. Best Mr Watson