Library /sys$common/syshlp/dce$cdsbrowser.hlb Overview, file  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Use the File menu to expand or collapse all directories
  or to exit the Browser.

  Choose the Expand All option to open all directories
  on all levels at once. Use Expand All with care if you
  have a large namespace. The larger a namespace, the
  longer it takes to display its entire contents.

  Choose Collapse All to close an expanded namespace.

  Additional Information (explode) :

• expand_all
• collapse_all