You can have dozens of To Do lists in your account. Normally when you view an individual To Do List you will view only the Tasks belonging to that To Do list. However, you can also see all of your Tasks from all To Do Lists in your account at once. This enables you to see all of your deadlines at once rather than looking at individual lists. To see all of your Tasks at once follow the steps in the image below:
When you view all of your Tasks at once you can also still use the Task filters available to individual lists to find only the groups of Tasks that you're looking for. To go out of the "All Task" view all you need to do is click on the name of the To Do List you want to see in the Navigator.