Since the Notes field is a text field, the search shouldn't be limited to one word or the exact text entered. For Example, I would love to be able to search for expenses that have the words "John" and "Car" to see every expense that has the words "John" and "Car" entered in the notes field.

If this isn't possible another alternative would be a "Tags" field within expenses, where the user can tag every expense transaction with multiple related words for search later.