/noderefdepth

[custom drupal module] Provides a filter/argument for node references that can take depth in (like taxonomy terms can). Warning: lookup of nodes is currently inefficent. 

Node reference depth [noderefdepth]

Provides an argument and filter (separate from ones provided
by cck) that take in depth; ie it searches for parents/children
of the argument/filter and includes them also.

Warning, lookup is currently SLOW.