Buddypress Signup Field: Private/Public

Trying to create a signup page that has field for publically displayed info and fields for info that just gets collected by the admins. It's for a charity walk. So far example, we want to be able to collect mailing address details but only show the 'city' and 'state' fields on the users' public profiles. The whole information (in this case, "street address," "state" and "city") should be able to be easily collected by the admins.

Any thoughts?? It's for a good cause and I'm a bit overwhelmed.