Can't access host folders from container

So I have a server running Ubuntu Server 16.04 and started the process of transfering apps to Docker containers which has been working just great except for 2 apps that won’t access folders in the host. Programs like SickRage and Sabnzbd have no problem creating and moving files to the host but apps like CouchPotato and ruTorrent won’t let me. I’ve read a few tutorials but still dont understand how to do it. I tried this tutorial