When you are having two face accounts while you are chatting in one account, if you want to chat from another account. You need to logout from current account and login to next Facebook account.
To get rid of this we have a wonderful solution.
You can logging to one messenger while chatting from another account.
For this we need to open messenger and click on profile which will be right side.
Click on plus symbol and login to anther messenger account and enjoy your chatting with second messenger also.