Giving access to CCTV cameras

hi,

Pre-requisites
-Main building - 32 cameras / hikvision / running on seperate CCTV POE switch /
-Sub Unit - 8 cameras / dahua / POE cameras /Has their own internet

We have a site which is a serviced office building. It has pfsense running all the CCTV equipment running on an isolated VLAN 10.101.0.0/24

The sub unit wants access to some of the hikvision cameras running on the 10.101.0.0/24
Most NVRS have 2 subnet networks i understand this and how to add the camera etc.

I am not sure how best to set this up on the network side. If i set up the sub unit with the same subnet as 10.101.0.0/24 i will be able to add the cameras by linking the 2 networks but this would cause a DHCP conflict and a security concern. I only want the subunit to access the camera IPs i decide.

Does anyone know how to best handle this?

thank you