Pretty sure that is the obi-ani or eclipse spin you are talking about. It is two rotations behind your back and one in front of you. If done with a turn, it looks a lot more complicated than it is.
If Scila and I are right about what it is you are talking about, this might help.
And this might give you pretty much exactly the move
If that is not it, can you give us a clip of what you mean?
I think it is. Here's the video.
You can see Dooku do it very swiftly at 1:34 and 1:45 marks.
Also, Cephalus, I've seen your Youtube channel! You're a great saber/sword enthusiast, and this is your first reply to me! 😎👍