Reviewing Permissions for users can be a daunting task. If you are needing assistance with this process, please feel free to contact the Unity PM Support team for assistance.

Below is a scenario of how to find where a user is receiving access to specific object.

Scenario: A user has Delete access for Disbursements which needs to be revoked. 

To find the source of this access, go to the User's page then click View Summary.

Select Object Permissions and search for Disbursements to view a summary of their access levels. We can see the user has delete access for this object.

Click on the Access Granted By link which will show you the relevant permission providing this access. In this case, delete access is provided by the General Permissions permission set.