Protected Environments do not support invited subgroups

Summary

Subgroup invited to another group can't be assigned Allowed to Deploy permissions at CI/CD Protected environments page (Both Group and Project level).

Steps to reproduce

There are 2 groups: Group1 and Group2
There is a subgroup of Group1: Subgroup1_1
Subgroup1_1 is invited to Group2 in Maintainer role.

Group2 -> Settings -> CI/CD -> Protected Environments -> Allowed to deploy dropdown is empty. Group2 -> Some Project -> Settings -> CI/CD -> Protected Environments -> Allowed to deploy doesn't contain Subgroup1_1.

Example Project

Protected environments are not available in free version.

What is the current bug behavior?

See STR

What is the expected correct behavior?

Subgroup1_1 is present in "Allowed to deploy" dropdown and can be assigned respective permissions.

Relevant logs and/or screenshots

Results of GitLab environment info

GitLab Enterprise Edition 15.6.8-ee