This is a member of the Viber Development Team!
This has been brought to our attention. However, at this moment this option is not available.
Meanwhile, we invite you to enter our Feature Request page and post your suggestion there, or join an existing similar suggestion. The more people join on a request, the faster it will become reality
You can find it here: Have an idea for a new feature? | Viber Support
If you have any question about Viber - please feel free to ask.