Clarify documentation about whether the "restrict group access by domain" option is available to subgroups
Problem to solve
Currently, https://docs.gitlab.com/ee/user/group/access_and_permissions.html#restrict-group-access-by-domain says:
To restrict group access by domain: Go to the group’s Settings > General page.
This implies that the option is available to any group, which I thought included subgroups — but from my testing it appears this option is only available to top-level groups, not subgroups. On #14004 (comment 520472977), @jrreid says:
One can define an email domain allowlist at the top-level namespace only. Subgroups do not offer the ability to define an alternative allowlist.
Proposal
I think it would help to clarify that you must "Go to the top-level group's Settings > General page" (or some other wording that more precisely reflects the actual functionality).