I had a look at the code and I scripted something amateur, so it could be not complete (i.e. it doesn't load sticky) or not secure but it works so far. Anyway if anyone want to build an interface/product over it be my guest.
This version is tested on vB 3.8.x
Use this plugin at your own risk.
How to use it:
Upload it into
Plugins & Products >
Import Plugin Definitions XML File
Go to
Plugins & Products >
Plugin Manager >
Forumlink (Forums as Categories)
edit this part
Code:
$forumlinks = array(
//'50' => 52,
//'52' => 50
);
using forumids you want to link, this way:
Code:
$forumlinks = array(
'20' => 22,
'22' => 20
);
Save it and activate it.