BuddyPress.org

Hi there, Those are not features that come with the base plugin, but you can enable them with plugins, BP Registration Options holds users pending and sends an email to the main admin, you could use this with either a group email address or a wp_mail filter to forward it to the other admins.

There’s a range of different private membership plugins, Simple Private springs to mind, which allow you to take differing levels of privacy to your site.