Like Smart Lists in Reminders there is a similar feature in Apple Notes called Smart Folders. They make use of the newly-added tagging tool in iOS 15.
Smart Folders in Apple Notes
The feature is fairly simple: Once you open Notes and navigate to the Folders screen, you’ll see a folder icon on the bottom-left. Tap the icon and a menu will appear with the option to create a new smart folder or new manual folder.
Selecting Smart Folder will bring you to a screen to name the folder and choose the Tag(s). Then, the next time you create a note with that tag they will appear in the Smart Folder. You’ll find Smart Folders in the regular list of folders with a gear icon instead of a folder icon.