Choose the Expand All option from the File menu to
  expand (open) all directories on all levels at once.
  When you use this option, you see the contents of all
  of the directories to which you have read access.

  Object entries can represent nodes, clearinghouses or
  any resource for which a client application creates an
  entry in the namespace.

  Note: Use Expand All with care if you have a large
  namespace. The larger a namespace, the longer it takes
  to display its entire contents.

  For information about other ways to expand a single
  directory or selected groups of directories, see the
  Help topic, Displaying the Namespace.