Answer by Jeremy French for Drupal: cck taxonomy field with depth filtering

Published by jeremyfrench on Mon, 02/22/2010 - 16:08

You could use taxonomy_get_tree() with the $parent argument of the term to get a list of terms and then use that in a WHERE x IN () clause, this is ugly and will be limited to a certain number of terms, but will do what you want.

You may find that solr will do this out of the box, but I don't know that for sure.