Transform a list with sublists

Hi,
I need to make lists depending of " List[0]", in fact when list[0] in all sublists is OA I want to create a new list with the informations below, and I want the same when it’s 25 in list[0].
So I need 2 lists “OA” and “25” with many sublists containing other informations like :

OA
0 List
12/06/2019 …
20,60
1 List
12/06/2019 …
20,10

25
0 List
12/06/2019 …
19,30

I don’t know if it’s clear

Capture

GroupByKey is probably what you want. Get the values at index 0 and then group the sublists that way.