Yes that are difficult to add.
On node both inside the building shape, if they are close to each other, possible only one will be shown on the regular map. Put the level:ref to it see:
https://wiki.openstreetmap.org/wiki/Key:level:ref
The other perhaps also on node:
https://wiki.openstreetmap.org/wiki/Tag:amenity%3Darts_centre
Best regards