Huawei introduced the tri-rear camera to the world earlier this year and has since been copied by Samsung and LG. No company has attempted to implement three selfie cameras, though, but we could see one such device in the near future, one produced by an unlikely OEM.
https://www.notebookcheck.net/There-s-a-triple-selfie-camera-phone-coming-and-it-could-very-well-be-made-by-Xiaomi.365741.0.html