Normally, the Auto-Adjust workflow type shifts dependent tasks; that is, when you change the Due Date of a task, the Start and Due Dates of all of its dependents are shifted by the same amount of time. This behavior can be applied to subtasks exactly the same as it is for top-level tasks. To include subtasks in this way, be sure to select Both top-level tasks and subtasks in your Apply this workflow to selection (for more, see Including subtasks in your workflows).
Alternately, when setting up an Auto-Adjust Workflow for a project, you have the option of choosing Treat subtasks as dependent tasks of their parent. This option is useful when you want all subtasks in your project to act like dependents of their parent task. If you enable it, then instead of having to explicitly mark all subtasks as dependents of their parent, Flowsana will treat all subtasks as if you had marked them all as dependent; that is, if you change the Start/Due Date of a task in the project and that task has subtasks, then the Start and Due Dates of all of those subtasks will be shifted the same number of days that you moved their parent task.
Note: If you select this Treat subtasks as dependent tasks of their parent option, the Apply this workflow to selection is no longer shown as it's not relevant when using this option.