Here you can find "zwischengeschoss" which in osm is it's own layer.
https://plans.trafimage.ch/zuerich-hb?identifier=geo-bahnhofkirche-and-raum-der-stille-c07b&lang=de&layer=zurich_innenplan&x=683058.47&y=247940.33&z=18.266463676788494