Filter tickets by responsibility
Identical to the responsibility drop down under "Tasks"
This feature is available in Version 4.
Tom Swogger commented
I think this should let you filter by any or all possible categories. If I want to see all tickets of a certain type belonging to two specific people, I should be able to do that. So instead of a dropdown for each filter type, I would propose checkboxes for showing any combination of filters. Open, closed, owned by so-and-so, category, priority etc.