Sub Grouping Objects in Branch

I have a series of channels that vary in shape and size. Each channel has a bolt running through it represented by a curve. There are duplicates of each channel type and bolt location .

I have no problem grouping the channels into branches(same channel type). I am getting stuck dividing the channel branches into further branched based on the the bolt location. I get the feeling I am missing a graft/trim tree somewhere but cannot figure it out.

Any help is appreciated


Group Channels.3dm (4.2 MB)
Group Channel.gh (29.1 KB)