Limit viewable users to group when adding

I would really like to have the option of limiting the user's I'm adding to a sub-group to just the members of our organization (the parent group).

Use Case:

• We like to give all developers lower-level access to the organization's group so they can see what is happening in the company but not make any major changes or access CI variables at the root level.
• In different sub-groups, we will give users higher levels of permission as needed.
• When we go to add a user to a sub-group, the user search box provided by Gitlab is global showing both public and internal users.

I would like to be able to filter the users in the autocomplete feature to just users in our parent group (or with a certain email domain...eg: @mycompany.com email addresses only).