Hello
I am not sure of what you want, but here is something that works better. It is important you understand “Datatrees” if you see multiple branches in your data, Grasshopper will think you want to make multi works not just one. So flatten data input.
If you see that it is not good => 2 differents jobs for Grasshopper.A “branch” is like a “for”
You must see this for this component, the same for shortest walk
Cocoon is very good, but here I used Dendro, that is more robust. .I use GraphMapper to make variation on branches radius.
20180228BRANCHING.gh (22.8 KB)
You could surely use my script to make realist branches (of tree) radius
See there