Yes, you can use more filters. It will only trigger the profile if all filters are met, so using APP = Gmail and Text = Hello! you will only intercept notifictions from gmail which have Hello! in the notification text. You could use regex matching but it really isn't neccasary.
Do note though that it will only try to match the notification text, which usually doesn't contain the whole e-mail, so you will only be able to match the first few lines.