Tech tree ?

[Akka]

I've looked in the forum to see if this question have already been asked, but I did not find it. Perhaps that I'm just blind, but well

I would like to know, when I create a new tech, how can I put it at a precise place in the tech tree. Samely, how can I move a tech on it.
Beware : I don't talk about the prerequisite, I talk about the visual location of the tech on the tech tree.

Thanks in advance