To manage community group notifications, open your account settings by tapping on the cog wheel icon (⚙) in the upper right corner of the ME page.
Look for "Notifications and Preferences".
Tap "Off" to create a check mark (✔) to silence "Community Notifications".
To manage chat group notifications, Tap on "Community" in the app.
Find the chat group you want to manage and tap on the title.
Then look for "Community Notifications".
Tap "Off" to create a check mark (✔) to silence notifications from this chat group.