Search Within Notes
The first attached screenshot illustrates where you can find the "Find & Replace" feature on the notes toolbar.
Please note that I'm currently using the fully expanded toolbar which is a preference setting available under:
- Options > Preferences > Note Editor > User Interface > UNcheck compact toolbar option. (Second screenshot)
If you are using the compact toolbar, the "Find & Replace" option will be available on the pull down hamburger menu (Third screenshot)