In looking at this, the Incident object does not carry a transfer date field, so one way I could envision this working would be to include customisation in which code is executed whenever one does a transfer to write the date/time of the transfer onto a custom transfer date field
One of the problems I am noticing is that the date field you are interested in copying is from the incident activity log, which is a separate object from the incident object itself. Further, it is conceivable that an incident can be transferred multiple times, so it would be ambiguous which date you would want to pull from the activity log, if it was the first transfer, the latest transfer, or something in between.