Need to hide old assignments after Global Transfer

Summary:

We have the business need where when we have a person in the UK move to the US, then after that Global Transfer only the US Roles should be able to see this person's Assignment data. However, if anyone had access to the UK record, when they search they can see the new US one.

Content (required):

We have Custom Roles set up that are based on Person Security and only allowing viewing rights for employees based on their LDG. This works for the UI and Reports, and when a UK HR person searches they only see UK employees. However, we have found that if we have a UK employee that has moved to the US and we perform a Global Transfer, then the UK HR person can still see this person when they search and see the new Assignment in the US. We have tried to use the "Active, suspended, or most recently