Search people according to level

I have set up Membership on my Buddypress site. I am using BP Profile search to search for users of a particular role. I now want to be able to set the search to limit to only users of a particular level (premium membership) I don't want users to select the level on the search settings, but as administrator I want to configure that the search should not pick "unpaid members" or something like that. That is the only remaining key configuration on my site, please help. The alternative would be allow all users to be searched (as the case is now) but when a user then clicks on the profile of an "unpaid member" they should be redirected to a "restricted access page".

Please note that I know nothing about code, if you will prescribe code, please give specific instructions of how and where to put the code otherwise I am ready to give you access to my web server and wordpress admin panel.

Thank you