Currently, dapulse does not offer subtasks, but this may change in the future. In the meantime, if your projects are dependent on certain tasks completion, please utilize the "Search Everything" feature. Search everything allows you do just that, search for your name, a particular status, a specific date, etc.
**NOTE: This feature is part of the 30 day free trial and offered in the Standard and Pro plans thereafter. View our pricing options here :)
Alternatively, create a Projects Board that will show your projects and the stages it must go through.
From there, you can do is create a board called "Sub Tasks" and then add the sub-tasks as pulses and the Project name it belongs to as the group title.
Finally, type in the project name at the top of the screen where it says "Search Everything", and you will see the Project, the stage it's in, and all the tasks associated with it.