Would be a new drop down in the stations section. As it stands you can choose the countries you have stations in, but you cannot narrow it down to State/Province. For example in Brazil, we have numerous states. It would be nice, to be able to drop down one more level, making it easier to plot a filler flight. I’m not sure how difficult this would be, but I am sure many would appreciate it.
I heartily agree, but I'd also like a "not" filter so that I can see all international stations at a glance too.