ToDo App - Task Membership of Lists & Groups

There does not seem to be a way to assign a task to a list or change the membership of a task from one list to another list. You can assign a task to a list by opening the list and then adding the task to the list. You can also assign a task to a list when you copy a task. Also there does not seem to be a way to sort or filter tasks by lists or by a group of lists.