[Q] Can't find TWRP folder or backup topic

I am having trouble finding my nandroid backup file made with TWRP. I can't even find the TWRP directory! This file system is so confusing! I have tried ES File Explorer, Root Browser, and tried searching the file system using my laptop. I have even searched for "2014-12-13" and nothing is found. Can anyone please help? Nexus 5 on Android 5.0 w/ TWRP v2.8.1.0