How to deal with required fields for different type of users

Scenario:
1) Tab A - visible only to userA in groupA with AL for A - with field#1 being required
2) Tab B - same for B - except, no fields in Tab A are required for that user

In back-end, when i try to update user B I'm getting the error to update the required field.

Note: to complicate the story, users are registered by Administrators and field#1 is not required nor visible at registration (i.e. the value might not be known to the admin) -> to work around this, the admin registers the user via the Joomla registration, instead of CB -> But, I would actually like to know if there is a workaround this as well

Is there a way to specify the required field is only required for one type of users/groups? how do I go about it?
thanks!

I recommend disabling validation in backend so administrators do not have to complete required fields beyond the core fields when editing a user in backend. This is done by setting "Fields Validation in User Management" to "No" within CB > Configuration > User Profile. This will have no affect on frontend though.

Is there a way to specify the required field is only required for one type of users/groups? how do I go about it?
thanks!

No, not unless you hide the field entirely using CB Conditional.