How to apply group policy to cross computers and users?

Question

System administration

Hello!
The domain now has such an organization: computers of different departments are scattered over their OUs, and all users are located in a separate OU. Thus, they do not overlap.
You need to apply a group policy for a specific user group (security group) and a specific computer OU.
Now it turns out to create it in the root of the domain and apply it to a group of users - this option works. But I would like, of course, to exclude the possibility of applying the policy for users who decide to log in from computers in another department.
The domain controller is Windows Server 2012 R2.

Answer 1

if I understand the task correctly:
bind the policy to the desired OU of computers.
Set filtering on a security group with a list of users, removing authenticated users from there