This scope lets an app "Access content in your private channels"
This OAuth permission scope works with these Web API methods and Events API events.
groups.history - Fetches history of messages and events from a private channel.groups.replies - Retrieve a thread of messages posted to a private channelchannel_history_changed - Bulk updates were made to a channel's historygroup_history_changed - Bulk updates were made to a private channel's historymessage - A message was sent to a channelmessage.groups - A message was posted to a private channel