How do I mount multiple NAS drives under 1 virtual volume

I have successfully mounted multiple NAS drives as separate volumes under NitoTV.

However - I would prefer to view all of my drives concatenated as one virtual drive (e.g. NAS1 contains Movies A-L NAS2 contains Movies M-Z – Prefer to see Volume NAS-V - Movies A-Z – i.e. the contents of both 1&2 in one mount).

Is this possible? If so - any tips as to how to accomplish the task?

Thanks