Groups is one of the most popular features of Viber, but sometimes the notifications can get annoying. You can mute or turn off notifications on Viber for Android for a specific group, by doing as follows:
1. Open Viber on your Android device (make sure you have the latest version)
2. Open the Group you'd like to mute the notifications
3. Go the Settings, by tapping the Gear icon on the top menu
4. Mark the Mute Group option and you'll no longer receive notifications for the new messages on that specific group
While you can easily turn off/turn on notifications for each group separately, there is no way to disable receiving notifications for a specific single conversation. But you can completely disable receiving notifications for new messages on Viber for Android, by doing as follows:
1. Go to Settings >> Apps and the find and open Viber. Now make sure to disable the "Show notifications" option
2. Now open Viber application, go to the app's settings and then the Notifications settings
3. Unmark these options: "Show message preview", "New Message Popup" and "Light screen for messages"
4. Mark the "Use system sounds", tap the "Notification sound" and set it to Silent.
5. Done! You'll no longer receive notifications on Viber for Android including message preview, message notification's sound and popup message