You can run reports that return information about pay zones and pay zone differentials in Reporting and Analytics > Reporting > Reports. See Ad Hoc Report Administration.
Employee Details - Payzones Report
The Employee Details - Payzones report evaluates the pay zones hierarchy to determine which zone is assigned to an employee at any point in time. This report initially returns all pay zone related employee data, which can then be filtered based on any attribute in the report.
To run the report, select Employee Details - Payzones Report in the Human Resources category of Reporting and Analytics > Reporting > Reports.