User profile page access from different domain

Hi there,

I would like to know whether there is a way to restrict users of one domain from viewing the profile page of users of another domain? i.e. if user A is a user of domain 123, he should not be able to view user B's profile if user B is not a user of domain 123 but domain 456.

I cannot find anything built in to support this. If I need to build custom code, can you please point me to the right direction? Thank you very much !!

Xin