Fuel transfer with what? That would require things like docking
They transferred something like 10 tonnes of fuel from one end of the ship to the other.
Transfer internally between tanks in the bottom and top of the ship. This was one of the planned tests, I have not heard whether it was accomplished though.
There was a callout saying that it was successful.
Edit: On the other hand tweets from Gwynne suggest that they still need to review the data to see if it was a success.
They performed an in-ship fuel transfer, from one chamber to another. My understanding is that this is a very important pre-requisite for an actual transfer from one ship to another, because of the need to keep the fuel at cryogenic temperatures during the transfer, which is apparently not easy. Last time it was done was decades ago, but in kilograms. SpaceX just demoed a transfer of tons of fuel.
Bigger problem than keeping it cryogenic is getting it to one side of the tank while in orbit, so the pumps don't run "dry". Harder than just doing an ullage burn first too, because moving that amount of mass around also moves the vehicle.
They used tanks inside the ship to transfer from 1 to another to prove the process, was discussed and called out as success, and talked about many times before the flight