Compensation Zones and Grade Differentials of an employee in BI

Summary:

How can I get the Compensation Zone and Grade Differential an employee is assigned to? I saw from previous posts that the details are in the CMP_ADDRESS_ZONES table, but how do I connect it to an employee's assignment? And aside from

Content (please ensure you mask any confidential information):

I have a reporting requirement that wishes to get employee's assignment information, as well as the Compensation Zone and Salary Grade Differentials. The salary information are available in CMP_SALARY and connected via Assignment ID, but how will I connect it to the CMP_ADDRESS_ZONES table? There is a Person ID in the table but it is currently blank. How will I also connect it to the Grade Differentials? Thank you.