I want to see everything in context X that is part of a project in folder Y
 

Most of my projects are either in my "work" folder or my "family" folder. Not that I can't do family stuff from work or work stuff from home, but often I want to focus on just work stuff at work, for instance.

So, I click on the "work" folder and there are the relevant projects. Now, what I really want to do is make phone calls. I have a context called "phone." Is there any good way to focus on my work phone calls?

Or have I set this up all wrong?

TIA

Click on the folder in the sidebar, then the Focus button in the toolbar. Now switch to context view, and click on the desired context in the sidebar. You will only see items in that context that are in projects in the folder on which you focused. If you don't want to do a whole folder, you can make a selection of projects by cmd-clicking in the usual Mac fashion before focusing.

Thanks!
 

Excellent. Just what I wanted.