Multi-level export

Would like to able to select exporting just the buildings when exporting multiple layers. (included ground level due to seemingly needing to make the ground the basement in the current iteration)
This way when importing to some VTTs the ground doesn't follow in additional layer making it partly unusable if you wanted to use univeral vtt with lighting.
-A potential second iteration would to include the terrain at the same height as the 2nd floor or additional floor so mountains can be there too.
-VTT using is DM Hub offshoot called the Codex

Thanks