Term Reference Tree

Forums:

  1. Enable the Term Reference Tree module.
  2. Go to the Manage Fields tab of any fieldable entity (such as a content type, taxonomy term, or user.
  3. Add a new field with a type of Term Reference.
  4. In the widget select box, select Term reference tree.

Note that you can also change any Term Reference field to use the Term Reference Tree widget, by editing that field and selecting Term Reference Tree on that field's Widget Type tab.

If you want to filter by a view, make sure the view includes the taxonomy term ID, and that the items per page is set to unlimited, as the widget will only display the items from the first page of results.

This module is also perfectly good for flat lists, particularly if you want to filter them by a view or limit the number of selectable options with JavaScript. I recommend turning on the "leaves only" option in this case, as it will make it look nicer.

 

http://drupal.org/project/term_reference_tree