A: Dear Jehoschua,

Thank you for your question. At this moment, you can go up to second level i.e. you can add tasks and subtasks, however you can not go any further.

For a task, you have:
Regular Task
Task -> Sub tasks
Repeat Task (habit based)

If I get more requests for the nested tasks feature, then I will get this implemented in our next release.

For now, I am going to make a note of this request from you.

Best Regards,
Siddhify Support