Roles Creation - MDG Rule-Based Workflow

Hello All,

I need to create roles for my rule based workflow as below. Please advise me how to proceed wither we need to create position or role or anything else?

I am using Rule-based workflow and I need to assign either role or position in User Agent Decision Table. At any single point of time I can assign only one REQUESTER to the Condition Alias. Then, how can I distinguish between Delhi requestor and Thamharam requestor as they should not see each other’s requests and the same case for approver. Delhi approver should see only his CRs.

Any one has done this kind of scenario so far? If so, please advice.