Extract items from a list of sublist keeping the reference number of the sublist

Hi everyone!!
Maybe there’s a super easy way to do this but I have no idea. I have a list of lists that are the result of an analysis. I need to keep the item number of the sublist when I select it using a range of numbers. For example select all the items that have values between 6 and 9. But I need to know the original number item of the selection because I have two result lists that are the same but one contain values and one points, and I will select the lists that I’m going to use by values but what I need for my code is the points that are linked to this values.

I don’t know if is clear, but please please try to help me.

forum-extract.gh (12.4 KB)

This outta do it, provided that your tree is only one layer deep {0}

You can also use list length + series to create a list of indices and parallel subdivide it to your original list