I have been struggling for days finding .NET Tree Data Structure, I have read many recomendation using C5 library, but I have yet find example for it.

I have read C5 documentation but didn't find example for it (I admit I haven't read all documentation page).
Edit: I need a Tree with basic functionality like search from parent to child node and vice versa.
If you only need the most basic functionality, then build your own data structure.
I did a quick implementation of a basic tree (directional edges and not necessarily binary tree), assuming you have a fixed root node. I also added methods for searching depth first and breadth first.