Mark walls by XY position - Unique sublists

[mellouze]

I think you can get some inspiration in this topic :

Set 'Mark' parameter to all elements in all model groups

[All groups] [Wall select]                                                 Hi, I recently started to work with Dynamo 0.9 for Revit 2016. I’d like to fill in the mark of all wall elements from a walltype in all groups in the model. (1 visible in the view, 20 groups not) Is this possible not using Python? Just Dynamo…