Virtual machines can be mapped or point to any managed device such as USB port or a USB host. This is particularly beneficial  when  used with the passthrough feature when a target device is mapped to a USB host. This can be accomplished in the following manner.

Under >Managed Devices > USB Port >

Enable

"Automatically map connected devices to Virtual Machine"  and add the exact host name under "Virtual Machine name:" This could be a virtual machine on the same device.

If running a virtual machine on a different Nodegrid devices then connect the 2 usb ports via Type A (male-to-male) connector.