At the flag level, I’ve never heard of one and I can’t ever foresee this happening. There are only about 1,000 flags throughout the U. S. military, and they just do not hop around.
The most senior that I’ve seen these moves is within medical. I have seen O-4s and O-5s transfer among the services, but not a lot. Part of the reason for that is that while you may get one of the Services to take you because they need your (medical) skill set, they generally won’t promote you, so you’ve dead ended yourself.