Gerben Wierda via ntg-context schrieb am 23.10.2021 um 15:20:
> I’d like a book with chapters to have sections/parts, e.g. something 
> that groups a few \chapter elements together. Is there support for 
> this in LMTX? I.e. in such a way that it also shows up in the table of 
> contents?

You can use \part.

Wolfgang