Restrict access between several networks

Sao

Hi, I need a help with access in several subnetworks.
We have an OpenVPN server with IP: 2.0.0.1 and with localnet address: 192.168.1.0 (Main)
Our partner A has 3 local networks: 192.200.1.0, 192.200.2.0, 192.200.3.0. Each one (local network) has themselves OpenVPN server and connected to our OpenVPN.
Then, we want to connect our new partner B which is also has themselves several local networks, there are: 172.16.1.0, 172.16.2.0. And in each network they has by 1 openVpn server.
The task is to connect all of them networks by OpenVPN to our server. Each network must has access to Main network and to the local network in themselves company (partner A) BUT not to the local network of the another company (partner B).

We currently connected them to our network and set setting site-to-site, "push route 192.168.1.0 255.255.255.0", now all work perfect! But if partner A (192.168.200.0) adds route 172.16.1.0, then he takes access to the local network of partner B. We must prevent this access and give it just to our Main OpenVPN server and network (192.168.1.0).
Please help!
Sorry for my English 🙂
Could we also assess the level of my English writing please?
Tank you very much!

Traffic

What OpenVPN Product are you using:
OpenVPN Access Server or OpenVPN Community Edition ?

Sao

Hi, I use Community Edition.
Sorry for large image, I didn't know how it will look.

Traffic

Sao wroteCould we also assess the level of my English writing please?

Your English is OK so far .. keep it up.

Sao wroteSorry for large image

Not to worry .. i have seen worse.

As for your main problem ..

Please see the Forum rules (top of page)

Also, you need to understand routing and iptables ... and OpenVPN

This example will help get you started:
HOWTO: Expanding the scope of the VPN to include additional machines

You may also need to implement some policy based routing as per this HOWTO article:
Configuring client-specific rules and access policies

With regard to your private network ID schema .. you may want to wikipedia: RFC1918