Do you have JIRA Software? Because this is only make sense with it. Well, lemme try help you.
I found this how to at Atlassian Knowledge: https://confluence.atlassian.com/jirakb/how-to-display-sub-task-below-the-parent-task-in-the-backlog-779158697.html
Maybe it will help you out.
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
We're bringing product updates and pro tips on teamwork to ten cities around the world.Save your spot