When an agent transfers in the MLS their TransactionDesk Documents stay with the broker. There are two ways that an agent can keep their documents, but they must be done BEFORE AN AGENT TRANSFERS!
Option #1:
If both broker and agent need access to the transactions there are a few options that can be done to ensure this is the case. One option would be before the agent moves offices they could archive the transactions onto their computer so they have access to a read-only copy. Then when the move actually happens the broker would have access to the transactions in that transaction transfer section and the agent would have the ones that were saved on the computer.
Option #2:
Another option that they have is before agents leave they can duplicate their transactions. Then when they are gone all transactions and duplicates would show in the broker account. The broker can then transfer them the original (or duplicates) and keep the other copy for themselves. Unfortunately, both options would need to be completed before the agent leaves the brokerage though.