VPN Master Server that accesses networks of every VPN Server

[Akito]

Is there a way to have several servers on one host with distinct subnets, except that there is another server that has access to all of the servers' subnets?

In this scenario the host would create 1 server per person. Though, the server needs access to all the servers' subnets and does not want to connect to every single server at the same time, as there will be tens/hundreds of servers, eventually.