Auto populate Termination date

Hi All,

We have a use case to auto populate the final close date on payroll relationship based on the termination date say 2 months after the termination date. Was anyone successful in achieving this?

We have tried using VBS and noticed that unless the fields are on the same page we cannot apply conditions on the fields to populate/apply conditions. 

Has anyone implemented this use case? If yes, kindly share how.

Thanks

Archana