In context of overlay "Places" – Westfield (Mall) – https://osm.org/relation/12609168 via StreetComplete 61.3:

There is a lot of chaos here with levels, e.g. parts of the same physical floor are tagged as 1 and other parts 2. I think the former matches how it's labelled on the signage (level:ref?). But regardless surely it shouldn't change part way along a floor?

#surveyme