VPN server with two subnet

Currently have my OpenVPN setup so that

all clients are connected to the same subnet ( 10.8.0.0/24 ) when they are connected to the server

I would like to change it so that I can assign each client into one of two subnets ( ie. client1 on 10.8.0.0/24 and client2 on 10.8.0.1/24 ) so that

Any help would be appreciated.

Thanks

BTW my topology is subnet

If you want to stop your clients from being able to see each other
then do not use --client-to-client and add appropriate firewall rules.

How do I set up two different subnets?

You cannot.

See --server in The Manual v24x

Start here:
HOWTO: For OpenVPN Community Edition