You can not retrieve a module role in a microflow, you can however retrieve a userrole with the current user.
Module roles no. But you can retrieve the roles of the user or all the roles.
Roles are stored in the entity “UserRole”.
Can be retrieved over the association "Userroles” for any user.
What do you want to achieve by retrieving module roles? I’m pretty sure there is a best practice without retrieving module roles.