custom-add-parent-links

custom-add-parent-links is a compiled Lisp function in `cus-edit.el'.

(custom-add-parent-links WIDGET &optional INITIAL-STRING DOC-INITIAL-STRING)

Add "Parent groups: ..." to WIDGET if the group has parents.
The value is non-nil if any parents were found.
If INITIAL-STRING is non-nil, use that rather than "Parent groups:".