You can add tags to your reminders to keep them organized, then use the tag browser to find tagged reminders across your lists. Tags are available for reminders that you’ve created in your iCloud account.
To learn more about this topic, visit the following articles:
Organize reminders on your iPhone, iPad, and iPod touch: https://apple.co/3KoYVwq
Use reminders on your iPhone, iPad, and iPod touch: https://apple.co/3Kr8V8c
Reminders User Guide for Mac: https://apple.co/3hO14FA
Additional Resources:
GetSupport for iPhone: http://apple.co/iPhone
To subscribe to this channel: https://www.youtube.com/c/AppleSupport
To download the Apple Support app: http://apple.co/2hFtzIv
Apple Support on Twitter: https://twitter.com/AppleSupport