here is the code to solve this:

Hierarchy:
TypeA
-TypeB (has nodereference field typeb_to_typea) this field shows the name of node a
--TypeC (has nodereference field typec_to_typeb) this field shows the name of node b

install Computed Field module, make a computed field in content type typeC, and put this in it:

$mytempvar=db_result(db_query("SELECT
field_typeb_to_typea_nid FROM content_type_typeb WHERE
nid=%d",$node->field_typec_to_typeb[0][nid]));

$node_field[0]['value']=db_result(db_query("SELECT title FROM node WHERE nid=%d", $mytempvar));

(returns node Title) Note: look at Hierarchy above and depending on what fields you use in your content types and what their names are, you will have to change
field_typeb_to_typea_nid
to
field_your_field_name_nid (attach the _nid to whatever the name of your field is, your field should start with field_ no matter what)
also
content_type_typeb
to
content_type_yourtype (content_type_ + whatever your type is)
also
field_typec_to_typeb
to
field_your_field_name (your field should start with field_ )

if you want to return the node Number/ID instead, do this (same field name rules apply to this as the code above):

$node_field[0]['value'] = db_result(db_query("SELECT
field_typeb_to_typea_nid FROM content_type_typeb WHERE
nid=%d",$node->field_typec_to_typeb[0][nid]));

(returns node ID #)