Currently there is no way to trigger an automation of a parent task based on the status or any other field change of its subtasks. For example, I want to create an automation for once a certain subtask is marked complete, the parent task status changes to a certain status.
If you set up a trigger based on a subtask, the only action it can take is on the subtask, but it cannot take any action on the parent task.
The closest thing currently is using dependencies, but that doesn't work when there are multiple subtasks