VPN help? How do I connect to local devices?

I'm not sure if this is the right community to ask, but I'm going to try anyway.

So, my Asus Router has smb file server, and vpn server feature, and I have a cctv unit connected to the router as well.

I believe have set up the vpn, port forwarding etc correctly... check the public ip is already the same. But how do I access the smb and my cctv? I've tried the local ip (192.168.50.xxx) with no luck, neither is the public ip (which make sense).

Any info or guidance is much appreciated.