Node Location Relationship | drupal.org

This views module creates a relationship that ties the location of a referenced node to the referring node.

The purpose of doing this may not be immediately obvious so imagine this scenario: There are two content types: Conference and Venue. The Venue content type has a location and Conference has a nodereference which refers to Venue nodes. Users will want to search for Conferences based on location but Conference does not have a location. This module will relate the location from the referenced Venue to the referring Conference so that users can search for Conferences based on location.

NOTE: A recent version of CCK made this functionality possible via the new "Content:" relationships. Using the "Content:" relationships, however, adds an extra JOIN in the SQL query which is undesirable from a performance perspective.