c-go-up-list-backward is a Lisp macro in `cc-defs.el'.

(c-go-up-list-backward &optional POS LIMIT)

Move the point to the position of the start of the list sexp containing POS,
or containing the point if POS is left out. Return t if such a
position exists, otherwise nil is returned and the point isn't moved.

A limit for the search may be given. The start position is assumed to
be after it.