Best way to group similar actions using Rails Routing?

I want to be able to group similar actions under one controller to keep things neat and clean.

For example, if I have a Game model, and I currently have:

resources :games do
  get 'schedule/previous', to: "Games#previous"
  get 'schedule/upcoming', to: "Games#upcoming"
  get 'schedule/calendar', to: "Games#calendar"
end

These obviously get more and more unweildy, especially because I have a bunch of other actions in my GamesController. How can I move these to a new controller (or otherwise organize them more cleanly)?

If possible I'd like to put the new "Schedule" controller under app/controllers/games/schedule_controller.rb or something like that.

I tried to do this using namespaces, scopes, and resources (and most of the combinations of two of those) and couldn't figure it out.