Validation for Location State value to be existing in the Entry Grade Name while creating a position

We have a scenario where we need to validate that when a position is being created, the State of the Location selected should be contained in the entry grade name. Is it possible to achieve this validation through VBS?

Eg: - Create Position

Location - Burwood Funerals

This location has an address and the state of this location address is VIC (Victoria)

Entry Grade - Australia VIC Funerals Tester

The validation has to fetch the location state and validate that value to be available in the Entry Grade Name selected, which in the above example is 'VIC'.

I have tried a simple validation rule but that doesn't seem to work.