User review restricted to buyer

Hi,

This question is regarding the User Review feature.

The functionality I’m looking to implement is:
1. You select a member in the site and pay him for coaching
2. You can put a review only to that member after the coaching has been held

I know how to restrict member review by role (coach and applicant), but I don’ know how to restrict the review to only the people that have paid and only to the coach that have helped them.

Is it possible with the plugin?

Thanks a lot in advance for your help!