Better support for multisite where individual subsites each have their own installs of BuddyPress

[tw2113]

Individual installs should only be listing pending users to their own install. Joe C with site 1 shouldn't be seeing a new user from Sam M's site 2, and vice versa.

Not an exact function to use, but the code in the following could show how to filter down to users of an individual site https://developer.wordpress.org/reference/functions/get_blogs_of_user