Preconditions allow you to execute a post function only under certain circumstances.In this use case, we want to copy fields to subtasks when the parent is transitioned. Since we didn't add any preconditions, let's leave this field at the default setting.

How to set up the Copy Value from Other Field post function

Learn how to set rules to:
1. Automatically set the Assignee from the transitioning issue to its subtask.
2. Copy the Summary field to a subtask Description on transition.

Post function configuration: Copy Value from Other Field