Some ideas to separate segments of similar length, in my case, the internalized curves in the red group I failed to separate them with Grasshopper

You can measure the length of all your curves, use those lengths to create a set of points `(x=length, y=0, z=0)`

. Then find groups of points based on proximity, but you have to pick the correct threshold. Then you can use the mapped indices to distribute your curves into groups of similar length: lengthgrouping.gh (20.7 KB)

OK perfect…Thanks!