Account Hierarchy in for partner Accounts

Summary:

We have below usecase from customer:

Account Hierarchy, and contacts could be part of child account or parent account (that are all part of same company). In this case, in PRM, 

1. Records visibility: we want Partner Sales user to have access only to their Opp (same as today), but Partner Principal to be able to see Opps for the full company - parent AND child companies. 
2. When we look at if a company has met their targets/goals, we will want to look at the full company tree (parent and child companies), not just an individual partner company. Partner Company Tiers are also dependent on how much business we get from them (them = parent and child companies)