Group list by index and another list and separate by equal parameters

[Tiago]

gl all

I need to create a list like the blue rectangle

[Alien]

So this post is pretty confusing…

Are you saying you want lists 1 + 2 joined first so you get:

blank
1
116
116
123
129
129
133
135
135
137
138
139

etc…

THEN you want to prefix this with the list shown in (3) the List.Join node?

I’m guessing you want to remove the blank and the 1 from lists 1 + 2?

In your output you’ve jumped from 123 to 133 then back to 129…

You have three 2s but only two 129s… How does this work?

Below is what I mean by list 1, 2 and 3.

[Tiago]

i need new list box

[Alien]

Maybe someone else can help then because I have no idea what you mean.

[Tiago]

see if you can understand now.

Ps.
empty items must be discarded

these values ​​0.8, 2 and n … are values ​​of a parameter contained in the mep families pipe fittings pipe connections, hydrosanitary parts, mechanical equipament.

the node getparameter guive me this error.