Theme hook suggestion for nodes within a menu link? I need nodes within a certain place in my menu to use a new node TPL file.

My menu is hierarchical like this.  

link1
link2
link3
-linkA
-linkB


I need nodes whose menu link is link3, linkA or linkB to use these new TPL files. 

I have 2 content types whose nodes can be in the menu and I need a different TPL file for each content type. These nodes can also be outside of the menu in which case they should use the normal TPL file.

So a node of content type A which has a menu link of link1, link2 or no menu link would use the default node--typeA.tpl.php. 

A node of content type A which has a menu link of link3, linkA or linkB would use node--typeA--special.tpl.php

A node of content type B which has a menu link of link1, link2 or no menu link would use the default node--typeB.tpl.php

A node of content type B which has a menu link of link3, linkA or linkB would use node--typeB--special.tpl.php

As I'm extending the node not page TPL I started with this: 

function MYTHEME_preprocess_node(&amp;$variables) {
  $variables['theme_hook_suggestions'][] = 'node__SOMETHING';
  kpr($variables);
}


Im assuming I need an if statement around the 2nd line which checks if the node is typeA and also in the correct place in the menu? However I had a look at the $variables on the screen and I couldn't see anything I could use to find out the menu position. 

I then looked at preprocess_page to see if it had a variable I could use. There is an array called main_menu which is the name of my menu. But it contains 0 elements. 

function MYTHEME_preprocess_page(&amp;$variables) {
  kpr($variables);
}
As this requirement may get even more complex, I would suggest adding a taxonomy selection to the content types in question. You can use this to assign the proper theme suggestions as the value will be saved on the node object. You may also want to check out ThemeKey.