Hey @mchalupnik, rooms cannot see what's going on in the other room unless this workaround may work. The host in the main room screen shares the breakout rooms (the observers).
With a breakout room in progress, you have the ability to share to breakout rooms. Also, keep in mind to have 'show my zoom windows to other participants when screen sharing' selected in the Zoom client settings > Share Screen.

_______________________________________________________
Leverage
cool features and
how to's from the
Community Help Center. If my reply helped, don't forget to click the
accept as solution button!
⤵️