Add a Group That Filters on Flags#1465

Allow the user to add a group (or groups) in the top left that filters for tasks with user defined labels.

Alternativly, add a static defualt group that has a predefined defualt label filter. I assume this couple work the same as the “Assigned to me” and “Due Today” groupings. But something more generic and based on a predefined label that could be added to any task.