Currently, Quick To-Do Pro doesn’t provide users with an ability to create sub-tasks. This functionality is planned for upcoming version 5.0, however, users of version 4.0 can manage their tasks efficiently as well.
There are several ways to attack the problem.
1) If you have only several major tasks and every other task is related to some sort of a big task, just create a project for each of the major task (menu Project >> Manage projects…).
Once the project is created, assign all relevant tasks to that project.
The biggest limitation of this solution is inability to create that structure one more level down because Quick To-Do Pro doesn’t allow creation of sub-projects.
2) Name your tasks accordingly.
Imagine you have a task of organising your holiday in France with few related tasks.
You assign that task to Personal project, which contains lots of other tasks. So you can not use solution 1).
You create a task “(France) Organise holiday”, where (France) is just a code to group tasks together. It could be a number, a unique key or anything you like.
Then you create several sub-tasks:
(France)1. Buy Lonely Planet Guide to France.
(France)2. Book flight
(France)3. Book a hotel
etc.
Now all of the tasks belong to the same major task “(France) Organise holiday”. All you have to do is to sort your task list by task name in order to see them side by side. Alternatively you can use menu View >> Find… in order to locate all tasks related to (acheter viagra France).