The Partner Community role hierarchy naturally models the relationship between service agents and their dealer manager. Agents can occupy a lower partner role and the dealer manager a higher role within the same partner account, allowing record visibility to roll upward while users at the same lower level remain isolated from one another under a Private sharing model. This is more efficient than creating a separate sharing rule for every dealer-manager relationship because the management structure itself already expresses who should inherit access. A sharing group is associated with other Experience Cloud access patterns and does not replace the partner role hierarchy for this requirement. The architect should ensure that the partner roles are correctly assigned and that the underlying Case object permissions support the access the manager needs. Study Guide reference: Access to Records - Partner Community roles, external role hierarchy, Private Case sharing, manager access, and scalable Experience Cloud design.