Limit Profile Custom Fields By Levels (use Xprofile vs s2Member fields)

I am trying to use level 0 for visitors, and levels 1-4 for paid members. The visitors are permitted to view and post in certain forums, but not the rest. The members are to have a set of custom fields associated with their profile, and visitors will not. Profile searches on these fields should return only members, not visitors. This is a BuddyPress site, and currently I’m using:

bbPress
BuddyPress XProfile Custom Fields
BP Profile Search
s2Member Pro

The problem I have is: I want a search capability that allows anyone to search the members by the custom field values. Using the XProfile fields I don’t see any way to restrict the searches to members since s2Member doesn’t know about XProfile fields. But when I add a custom field in s2Member, it doesn’t show up as a field option in BP Profile Search when I set up a form.

Any way to do this without a lot of custom coding?