Webinar Chat for Attendees only with Host and Cohost

As of now, I can not enable Chat for attendees to talk only with host and Cohosts.. It automatically adds hosts and Panelists. Which does not help me. 
How to separate panelist from hosts as we have critical information between attendee and host.. which we dont want to share with participant.

We cant use Q&A option too.. because it runs on same logic.
Please help