How do I remove one group of members from the member list

Hi - I am using Buddypress to develop a site to bring together patients and therapists. I want the members of my site to be able to view a list of therapists, but I do not want the therapists to view a list of members - in other words, there are two groups of people, and I only want one group to appear in the member list. any thoughts on how I can achieve this please?

I have used the Membership plugin to create two levels of subscription - one for members and one for therapists.