Actions taken on a task should be able to trigger changes to one or more subtasks of that task. Similarly, actions taken on a subtask should be able to trigger changes on the parent task, or sibling subtasks.
For instance, imagine a task representing an Ad Campaign, with a subtask for the Graphic Design, that has a custom field for tracking the Design Phase. I want an automation that is triggered when the Design Phase field is changed on my Graphic Design task, and then changes the status of the parent Ad Campaign task.