I got a tree with three branches in each a wall.

I got a tree with 1 branch with 11 strings as parameter names.

I got a tree with three branches with 11 items each as parameter values for each name.

I join them in a set parameter and apparently I get a tree with three branches each containing 11 walls BUT in revit there are just 3 walls created with the corresponding values in their 11 parameters each.

So the result is not problematic, and completely right

BUT I’d very much like the set parameter to create just the three walls inside grasshopper.

Anyhelp? Would be very much appreciated!