Different location for a My Cloud Folder

Hello guys, I’m setting my ex4100 for the first time, I will like to have one folder shared between two mac.
The NAS did that, but created a folder in my system drive (in the macPro), the problem is that the system drive is big enough for contain the Lightroom library, I want that folder in one other drive that I’m using only for lightroom. It’s that possible to do? the folder need to be update in both computer and need to be local in both.

From my side is not possible.