Calling a different controller from a view


Currently, I have a views/x/list.rhtml. Normally, one would post to
its controller, controllers/x_controller.rb, but I am actually posting
to controllers/y_controller.rb in order to call the list method of y,
create a filtered model for y, and display list view for y.

So, this works, but I understand that calling my y controller from my
view x is not the best architectural way to do things. So, I am
thinking that I need to post to x's controller using a method maybe
called "listy". listy will then invoke y controller's list method.

How do I do this? y controller's list method will also need to receive
a parameter from x controller's listy method.