Hello I am an independent advisor for the Microsoft community. You will only be able to pair 2 speakers to Windows if those speakers support the option to pair with each other. I found this link with instructions: https://www.wikihow.com/Connect-Two-Bluetooth-S...
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.