“Restrict Registration” is a plugin for WordPress that allows you to control 
who is registering on your blog. This plugin uses simple blacklists and 
whitelists to define who can register for your blog, and who is restricted. Use 
simple literal matching, flexible asterisk wildcard matching, or powerful 
regular expression matching: it’s your choice! The options page is clear and 
easy to use. Set your lists, and you’re done!
This plugin was inspired by WP-Deadbolt, but has been completely rewritten and 
redesigned, and several new features have been added.

Restrict Registration

Use simple blacklists and whitelists to control who can and cannot register on your blog.

SeventhQueen

New: Added the ability to give free access to some BuddyPress members based on specific profile field and value. 
Works with Paid memberships Pro.
This plugin helps you add restrictions for the following BuddyPress areas: 
* BuddyPress Members directory 
* Viewing other BuddyPress profiles 
* BuddyPress Group directory 
* Single BuddyPress Group page 
* Site-wide activity page
Paid Membership Pro integration. You can apply restrictions based on your already defined membership levels.

Restrictions for BuddyPress

Restrict BuddyPress pages or content for visitors or different membership plugins.

Restrict Registration vs Restrictions for BuddyPress