U2722DE, select Audio/Sound source with PBP/PIP?

When using the Audio Out to external speakers, together with PBP/PIP, only the active screen outputs sound.

Is there an option to select the audio output source?

For example - 

Laptop connected to USB-C input as Main Screen

Chromecast connected to HDMI and PIP in right corner

Chromecast playing youtube video - can see fine

Audio only active from Laptop in this set up.

Switch Chromecast to Main and then sound works from HDMI.

Would be nice to select the audio source

Thanks!