Traktor Pro 3 HID Setup

I've searched these forums but can't find my answer...

At the minute I'm using rekordbox in Export mode.
I have both my CDJ 2000NXS2 and DJM 900NXS2 connected as follows;
> USB from computer to DJM
> LAN cable from computer to LAN hub connected to both CDJs and Mixer

How can I connect to Traktor Pro 3 with a single USB cable? Is it even possible?
I have one spare USB socket to my computer - am I going to need a USB hub?