How to view historical benefits information of employees?

We have a specific situation where employees can transfer to a position that is not paid through us and have no benefits through us. In other words, they transfer to a position that has "Payroll System = Other" and "Benefits System = Not managed in PeopleSoft".

However, once we transfer the ex-employee into this type of position, we can no longer view the historical benefits system that the employee had while as an employee through us.

Is there another location where we can see this information? Otherwise what is the best practice for this situation so that it has no impact to payroll and benefits.