When editing blocking tasks, the selection view defaults to Assigned to Me (mostly useless in our workflow, as we try to limit the number of tasks people are assigned to at any given time). Created by Me is useful, but may often miss out on important tasks when several people are working together. "All Open" and "All Tasks" are too broad to be really useful filters.
Searching by name is of course useful, but presupposes that you know (or remember) the names of the tasks you're looking for.
A filter that I feel would be useful here is "All In Same Project(s)" which returns all tasks in the same project as the edited tasks.
Alternatively, some way to specify tasks in a specific project.