In the Reminders app, you can easily filter your items across lists using Smart Lists. You can create custom Smart Lists to automatically include items filtered by tags, dates, times, locations, flags, and priority. You can choose more than one tag (such as #gardening and #errands) and combine them with other filters.
Turn on or off the following Smart Lists:
Today: Items scheduled for today and overdue items
Scheduled: Items scheduled by date or time
All: All items across all your lists
Completed: Items with a checkmark
Assigned to Me: Items assigned to you in shared lists
Siri Suggestions: Suggested items detected in Mail and Messages
Flagged: Items with a flag
Go to the Reminders app Tag items in Reminders on iPadOrganize multiple lists in Reminders on iPad