Can I filter my notes?
Unfortunately, it's not possible to search or filter task notes. You're welcome to add a request for such feature to our Votebox: http://todoist.com/Vote/ and let us know how you would like it to work.
It should work the same way as task filter. But instead of q: (search word) could be n (note): search word. Or just the current filter can not only look at the tasks but also look at the notes.