Dual Openvpn tunnel on Centos?

Question

openvpn

I have:
First machine Linux openvpn server.
The second Linux client machine goes to the Internet through the first one.
The third desktop machine on windows.
Can the second client machine give keys to the third one (on windows) and pass it through itself so that the third one goes into and out of the ip of the first machine.

Sorry for the confusion, this is my first experience with openvpn and Linux :)
Tell me how to implement this? If it's not difficult, give a link to the manual.

Answer 1

If machine 3 has route 0.0.0.0/0 through 2(gateway). And 2 has route 0.0.0.0/0 through 1(gateway), why not.