Search form to find posts by P2P association

Right now I have two custom post types “Stores” and “Services”. I have a connection between them (services_to_stores) and it works perfectly. The problem is that I need a search form that shows all the stores that give the service “a” (for example), and not the service itself. I mean, if I have 10 stores that gives the service “a”, and I look for the name of the service, the search results have to show me the name of that 10 stores, and no the name of the service.

Is there’s a way to do that??
Thanks a lot

http://wordpress.org/extend/plugins/posts-to-posts/