If you are not familiar with the oc command, refer to OpenShift - Getting Started with the oc command.

Here is a basic illustration of how a user, group or service account get mapped to permissions.

The oc get groups command can be used to list the groups that have been created, and the members of each group.

~]$ oc get groups
NAME                          USERS
my-group-admins               john.doe
my-group-cluster-admins       jane.doe
my-group-cluster-status       jack.doe
my-group-cluster-readers      james.doe jasper.doe
my-group-editors              jackson.doe jordan.doe
my-group-self-provisioners    julie.doe jose.doe
my-group-viewers              josh.doe jeremy.doe

A group is almost always associated with a Role Binding so it might be a good design to have the groups match the Role Bindings.

The oc adm groups add-users command can be used to add users to a group.

~]$ oc adm groups add-users my-group-admins jacob.doe
group.user.openshift.io/my-group-admins added: "jacob.doe"

This one liner can be used to list the Cluster Role Bindings that have been mapped to the group. In this example the Cluster Role Binding named "my-role-admins" is mapped to my-group-admins.

~]$ for crb in `oc get clusterrolebindings | awk '{print $1'}`; do echo $crb; oc describe clusterrolebinding $crb | grep -i my_group; done;
my-role-admins
  Group  my-group-admins

Then the oc describe clusterrolebinding command can be used to show that Cluster Role Binding my-role-admins has group my-group-admins and role cluster-admin.

~]$ oc describe clusterrolebinding admin
Name:         admin
Labels:       <none>
Annotations:  <none>
Role:
  Kind:  ClusterRole
  Name:  admin
Subjects:
  Kind            Name              Namespace
  ----            ----              ---------
  Group           my-group-admins