This looks airport related (Area 2b+c maybe)😁
I don't think FME is the right choice for this.
Firstly, you cannot create a 3d donut polygon (not in FME's naming scheme), it must be a mesh or composite surface.
If you want to use FME this is the way:
Bufferer->3DForcer (by original elevation + 0.012*buffer value).
Original feature + 3Dforced buffer to Breaklines port of SurfaceModeller (output Triangles) -> Clippee port of Clipper and original Feature to Clipper port (Outside port) -> Triangulator (TIN Surface output port) -> MeshMerger.
Indeed it is.
Thank you so much for the response.