I\'m trying to figure out how to search within files containing only a certain extension and within a certain directory. I\'ve tried */app/*,*.jade, but that se
You are indeed correct that the Find in Files functionality allows you to provide a comma separated list of search terms and they are effectively an OR operation.
Note that you can also prefix a term with - to make it mean BUT NOT, which you can use to filter results out.
In order to find only files of a certain extension AND in a certain path, you need to create a search term that includes both of them at the same time:
*/app/*.jade