I want to use Reminders.app but I also want a little more structure through nested lists. How do I created nested lists with Reminders.app on iOS or OS X?
Unfortunately there is no support for nested lists in Reminders. I would recommend Todoist if you're looking for nested lists, it does a great job and integrates into OS X and iOS well. There are plenty of other aps that do this too like wunderlist and trello
I found a way but it only works on iOS 9. Simply ask Siri:
Remind me about this to X list.
While looking at reminders list Y and then list Y will be "nested" inside list X. I say "nested" because list Y will still be accessible from main view and not just list X.