2. Swipe down on your screen to acces your Quick Panel and tap on Media.
3. Ensure you have selected both Audio outputs to start playing music from both Bluetooth speakers.
4. Once connected you will be able to play the same audio from both devices and adjust the volume with ease.
To enable this feature:
Go to Settings > Connections > Bluetooth.
In Android Pie, tap Advanced. ...
Turn on the Dual Audio toggle switch.
To use Dual Audio, pair the phone with two speakers, two headphones, or one of each, and audio will stream to both.
If you add a third, the first paired device will be booted off.