Variable: org-columns-top-level-marker
org-columns-top-level-marker is a buffer-local variable defined in
org-colview.el.gz.
Documentation
Points to the position where current columns region starts.
Source Code
;; Defined in /usr/src/emacs/lisp/org/org-colview.el.gz
(defvar-local org-columns-top-level-marker nil
"Points to the position where current columns region starts.")