How to get only Hire and Rehire dates in Message Template of resource alerts?

We are building a Work Anniversary alert that is going to be sent to line managers. Our definition of work anniversary is the latest Hire or Rehire date of the worker. This means that any Global Transfer action that creates a new work relationship is not counted as an anniversary date.

We were able to create a filter to only get the latest Hire and Rehire date of a worker, however, the message template in the resource alert only allows us to use the HireDate REST API. This REST API gets the correct Hire and Rehire date, but for cases where the worker globally transferred, the date that it shows is the Global Transfer date, which is incorrect.