yeah…i have only tried on your sample with 3 levels and works great here…have you tried as i do the same ?
I would first try level by level … seems you already have issue with solids …and find out why 
have you tried my latest atttechment…there is updated for multiple
Yes i already try it, exactly what you did as per video. and im using your last dynamo attachment. hmmm its work very well at level 7 but not the other two levels…
and this is when i try multiple level
Update!
using the same way from your attachment, but i skip the flatten list node so its keeping the surface gruped per level, then i repeat the process but this time i use Polysurface.ByJoinedSurface node and im using Polycuve.byGroupedCurve node (not using archilab’s node). And the results worked as we wanted
I am deeply grateful for the invaluable assistance provided by @sovitek and @jacob.small. Thankyou very much !!
Edit: Turns out this works well on the 3 building levels, which I’ve shared. when I run it in a complete building it will error… hmm I thought it would run fine too
Edit 2: ive tried changing the lacing too still doesnt help… (warning nodes: element.solid: Polycurve_Branched: are not supported, Solid.ByUnion: Value cannot be null)
Hi @najwan.joan.sv hard to say with they other levels, try first levele by level until you find out where the issue is…something here for you 3 levels from sample file, here i try run on all these levels…
I see, i figured out why. my Solid.ByUnion operation failed and passthrough the value. whereas what is needed is one solid…
