Hi @Werner_Beck! As it stands, you can easily search for tasks unassigned by entering “Nobody” in the Assignee fields (see screenshot below). But the Advanced Search can’t search for “Active Tasks” as you you described. While we have a “Due date” and “Completion” field, there is currently no option to filter tasks out by start dates. I would suggest to add your vote to this thread from our #productfeedback category.
All the best,