If I have a kitchen cupboard that is tall and fitted to the wall, and which has doors and a set of shelves inside, that is a Schrank.
Is the above correct?
But what is an individual shelf called in the Schrank? Is it a Regal?
If I have something like a bookcase, a standing unit with shelves, that is a Regal. And an individual shelf is also a Regal.
Einlegeboden
Tablar https://www.duden.de/rechtschreibung/Tablar
the Germans use Regalbrett (when it is part of a shelf) or Schrankboden/Einlegeboden (when it is an a cupboard/wardrobe)
Chuchichäschtli...
Thx. Could you have a Regalbrett in a Schrank, or only on a Regal?
Only on (in?) a Regal. See above, I edited the answer accordingly. The Swiss Tablar on the other hand is universal.