Abo-abo has a post on swiper-all that everyone using swiper should read. It turns out that there’s a command called swiper-all that will perform the swiper search on all opened buffers. That is, on all buffers associated with a file. That’s a tremendously useful facility and if you have swiper installed you already have it. You can call it with 【Meta+x】 swiper-all or, if you think you’ll use it a lot, you can bind it to a key sequence.
If you aren’t a swiper user, take a look at Mike Zamansky’s video on searching with swiper to see how it works. You can also check out the swiper GitHub site and the documentation. I’ve been using it for about a month and really like it. Discovering swiper-all just makes it better.