Hi @Donat_Lanszki; Michael from Asana here.
I’m merging this question into a more appropriate thread to help keep out Community organized. That said, at the moment we do not have the ability to view all Tasks/Project deadlines in one place. The exception to this is your “My Tasks” list where all Tasks assigned to you will be shown.
We do have one workaround that isn’t perfect, but would allow you to view the Tasks of more than one Project into a a single space you can then view in Timeline mode.
I recommend creating a new master Project that will be home to all your Tasks from the Projects you wish to view in one place. Next multi-select (https://asana.com/guide/help/faq/multiselect) the Tasks from the Projects you wish to view in one space, and multi-home(https://asana.com/guide/help/tasks/fields#gl-multi-home) them into this single Project. Multi-homing these Tasks will add them to be viewed in your new Project. Once you click the timeline tab(https://asana.com/guide/help/premium/timeline), this will enable you to view all the Tasks, with due dates, to appear in one place.
It’s not perfect nor automatic, though should you need to see how the moving pieces of more than one Project in one space. Additionally the trouble with loading a single Project with so many Tasks is that it will significantly slow down the system and cause the system to lag. That said, this workaround could be quite useful for viewing the contents of 5 projects (or so) in one place should you need that kind of top down clarity.
Hope this helps!