One of the plugins I am using generates user meta from our AD. One of the keys is the user's Manager.
As many users will have the same manager, I want to be able to group all users.
I was trying to find any way to do this, or adapt this post: getting all values for a custom field key (cross-post) but can't wrap my head around SQL database writing.
Practically, I want to be able to loop each meta manager with all the users that have that