Hi TIG, thanks for the orientation.

Since I am a neophyte in sketchup programming, I will need more a step by step help. If you could give the code to copy in ruby and specify where to put the Z value to select component.

Is it made for edges or faces selection only or a whole component can be selected.

Does it select all components above or under the Z value or the component that are on this coordinate?

Thanks for more information, sorry not to catch at first pitch!
S.