Open WhatsApp
Go to the Chats tab
Find the group chat
Archive the group chat
On Android, long-press the group and tap Archive
On iPhone, swipe left on the group and tap Archive
To keep it hidden, turn on Keep Chats Archived in WhatsApp settings
Open WhatsApp Settings
Tap Chats
Enable Keep Chats Archived
To mute the group, open the group chat
Tap the group name
Tap Mute notifications
Select a duration
To leave the group, open the group chat
Tap the group name
Tap Exit Group
To remove the group from your chat list completely, delete the chat after exiting the group