Notebooks uses macOS Spotlight search for performing full text searches, listing items assigned to Contexts or Favorites, finding Recently Modified items and more. So when a search in Notebooks does not return any results, or when smart books are empty when they should not be, reindexing macOS Spotlight may help.
As of early 2023, we have observed that the new Dropbox application for macOS 12 (its document migration, to be precise) may also cause Spotlight to fail. We have prepared a dedicated article about this.
In any case, you can reindex Spotlight for a specific volume with a few simple steps.
- Open System Settings > Siri & Spotlight > Spotlight Privacy
(on macOS 12 and earlier, open System Preferences > Spotlight > Privacy)
- Add the volume containing your Notebooks documents (not just the directory) to the Privacy list.
- Wait a few seconds.
- Remove the volume from the Privacy list again.
- Spotlight starts to index the volume, which may take a while. To determine if Spotlight is still indexing, use cmd-space to open Spotlight and type a few characters; now wait about a second and you should see a progress bar indicating the progress.
When Spotlight has finished indexing the documents, search and everything else in Notebooks is supposed to work as usual.