I've connected my thumb drive via otg cable and installed ES File Explorer, but I still can't find the right directory for the thumb drive. In ES File Explorer there is a USB 2003 directory, but it never loads. It just keeps spinning and saying loading.
It seems it has some type of size limit restriction. If I only put a few rom on the flash drive, the usb thumb drive is accessible from ES File Explorer, but I have to copy and paste the rom files onto the Nexus Player's hard drive. I'm running out of space on this device, and I would like to be able to access my files via the usb directory instead of moving those files onto the Nexus Player.
Android Central claims it works, but I still haven't had any success http://www.androidcentral.com/about-nexus-player-and-usb-support#comment-form