Final answer:
A Salesforce Administrator can address private access settings for a custom object by configuring the role hierarchy to reflect the organizational structure and ensuring 'grant access using hierarchies' is enabled, allowing higher-level users to access records owned by subordinates. Sharing rules and manual sharing can provide additional access if required.
Step-by-step explanation:
To resolve the scenario where the organization-wide default setting for a custom object has been set as private, a Salesforce Administrator can utilize the functionality of the role hierarchy. Salesforce role hierarchy allows users at higher levels to access records owned by users below them. Therefore, to ensure users above others in the role hierarchy have proper access, the administrator needs to configure the role hierarchy in a manner that reflects the organizational structure and access requirements.
Each role in the hierarchy should be set up to have grant access using hierarchies enabled, which is the default setting for standard objects but can also be applied to custom objects. This allows users in higher roles to view, edit, and report on all data owned by or shared with users in roles below them in the hierarchy. If additional sharing beyond the hierarchy is needed, the administrator might consider creating sharing rules to grant access to specific user groups or using manual sharing to share individual records when necessary.