Synology routing on two subnets one behind the other

I have three Synologys NASs (NAS 1, NAS 2, NAS 3 ) each have two Ethernet ports LAN 1 and LAN 2.
I have two networks 192.168.2.0/24 and 192.168.200.0/24. NAS 1 LAN 1 and NAS 2 LAN 1 are on 192.168.2.0/24. NAS 1 LAN 2, NAS 2 LAN 2 and NAS3 LAN 1 and LAN 2 are on 192.168.200.0/24. I do not want NAS 3 LAN 1 or LAN 2 on network 192.168.2.0/24. How can I route (access) from 192.168.2.0/24 to NAS 3 behind NAS 1 and NAS 2?

No one out their have any idea how todo this?