Imagine to have two RESTful controllers (UsersController, OffersController) and a PagesController (used for static content such as index, about and so on) in your applicatio
Typically, I would abstract out the menuing functionality so that I have a helper method for rendering the Admin menu. This way, it's possible to throw as much logic in the helper as you want without clouding up your view logic.
So, your helper would look like (forgive the ruby/rails pseudo-code, it's been a month or two since I touched it):
def render_admin_menu()
if !current_path.contains('offer')
render :partial => 'shared/admin_menu'
end
end