[curt.clifton]

Originally Posted by Christian Roth

… I am still a bit puzzled to see that the basic system (i.e. without the use of perspectives) cannot handle real-world requirements easily.

I think Perspectives are a basic feature of OF. They're essential to making the system work for anything other than a basic list manager. Once you're considering hierarchical contexts you should be investigating perspectives. (I came to OF from Life Balance. Places in LB supported being in multiple contexts at once, much like Perspectives do in OF.)

Sorry I didn't think to mention perspectives in my original answer. I'm glad you discovered that solution!