Ask your question here if you can’t find the answer in the FAQ.

Forgive my ignorance ;) But could you please provide more details? Where is this and what is it? :)

You can find it in the community-created materials, if you have the Tribes of the East expansion. In the launcher, look for something like "Nival Interactive - Tribes of the East - Community Materials." There, you'll find a skill tree diagram with all the skills and their recommended progression.