Add new domain to ‘My Sites’ using network admin

In the rare case that someone needs this, I was able to accomplish extra sites but I had to do everything through the database (not ideal). Here’s the comment I left for myself in wp_config.php:

 /* If you need to add more domains to this installation it is sadly a 
 * ballache as there's no way of doing it through the admin. 

 * In the database you need to edit the following tables:

 * wp_site - add a new domain row (make note of site ID)
 * wp_sitemeta - duplicate all the new domain meta data
 * wp_blogs - add a new domain here, match the site_id foreign key

 * Then you need to duplicate the following tables:

 * wp_i_commentmeta
 * wp_i_comments
 * wp_i_links
 * wp_i_options
 * wp_i_postmeta
 * wp_i_posts
 * wp_i_term_relationships
 * wp_i_terms

 * Finally go into wp_users and ensure a wp_i_capabilities and wp_i_user_level
 * exists for your new site ID. You should then be able to see and edit your
 * new domain.