Shift list equivalent for tree branches

[anikolo (Aris)]

I don’t know if I’m expressing it right, but I need to perform an operation between groups of curves:

I want to find the intersection of each curve in a list with the equivalent curve in the next list. To me it resembles the ‘shift list’ component just with branches. Can somebody pls help me with that? (in the example, I only have three groups of curves but in reality I have many more and I need each group to intersect with the next)

I hope that makes sense…
shift list.gh (15.0 KB)

here is what I would do If I had just a list of curves instead of a tree:

[Joseph_Oster]

shift list_2018Jan26a.gh (21.5 KB)

[anikolo (Aris)]

Thanks Joseph,
but I think I found a solution: relative item.
I went through the tree components one more time and found it could do the job cleanly!
thanks for your help though!

shift list.gh (21.0 KB)

[Joseph_Oster]

This is a better way to use RelItem that avoids flatten and Partition (with a manually entered constant!?) in your code. See yellow group. The white group is my version with one more Flip added to match your results.

shift list_2018Jan26b.gh (28.5 KB)