accessing another controller's data

Hello everybody,
I'm ruby/ror newbie

I'm trying to generate a site map of a website. Website is divided to
three parts (each has own controller). In every controller(in init
action) is variable @left_menu, which is a hash containing a sub-
navigation of current part of the site.

The problem is that to generate the site-map i need to access
@left_menu in father controller (root) of those three previously
mentioned controllers.

Any ideas? Or am i approaching this wrong way?

HELLO I AM DEPRES AND CIK