I've created behavior tree system for Urho3D. This implementation is based on event-drivenBT from this video (~36 min)
You can get source code from here.
Also check out demo project for some basic intructions (especially source files for Example1 - right now I don't have time to write more detailed instruction).
If You are Windows(64 bits) user, You can get binary form of demo from here .
I hope You'll find this useful.