Dynamics CRM Portal Restrict Support Views

Hi, 

We are currently setting up the Dynamics 365 CRM portal. One problem we are having is restricting what portal users can see primarily relating to the Service section. 

What I am hoping to achieve is essentially 2 levels of permissions relating to accounts. 

Lets say I have 2 users Joe and Bob. Joe and bob work for the same Account Contoso' Joe is a supervisor and bob a lowly minion. 

I want to allow them both to be able to submit and view cases however I want Joe to be able to see all support cases for Contoso but bob to only be able to see the ones he is listed as a 'contact' on eg he submitted them.

Is this possible and how would I go about doing it?