As far as I know, you cannot reference module roles at runtime. I'm struggling to understand why you would need to do this - could you perhaps give a more concrete example of your intended functionality? That way we'll be able to guide you in the right direction.
Using the emailing function as suggested by mendix - we're looking to send emails to the 'Manager' role for a certain email.
For example, sending an email when a timesheet gets rejected. This needs to be sent to the timesheet owner and the managers. This can be done by grabbing the user roles from the system, then sending all associated accounts' the necessary emails. Only thing is, this is probably going to be done multiple times, so multiple project roles may need to be created to cover all of the email sending, we're just trying to avoid it on a project role level and moving it down to modules so as to not blk up the project user roles.