Contact upgrade with previous implementation

I am using beacon proxy pattern and have upgraded my contract to new implementation

Now, i want to use previous implementation by upgrading contract. How shall I achieve it.

If you want to roll back, you should get the address of the previous implementation and do another upgrade setting it to that address.

UpgradeBeacon method has beacon address argument. What parameters shall i pass to rollback previous implementation

Do you mean the upgradeTo method on the beacon?

You should find the address of the previous implementation and use that as the argument. If you don't have a record of this address, you can recover it from the logs in Etherscan or the appropriate block explorer. Is there a link that you can share?

How shall I find all the proxy address connected to given beacon?

You need to share a lot more detail for us to be able to help. What tools are you using? How did you deploy the proxy?