Same SSH tunnel for multiple hosts

I am super new on SSH and I want to create an SSH tunnel that transfers multiple ports. Let's say I have three hosts so instead of transferring ports like A-> B-> C, I should be able to connect any of these servers.

Imagine master-slave and A is master where B and C are slaves. If A goes down then I want to connect to B or C. So it will not be like a serial connection like A-> B-> C but rather a kind of parallel connection.