This OAuth permission scope works with these Web API methods and Events API events.
mpim.history - Fetches history of messages and events from a multiparty direct message.mpim.replies - Retrieve a thread of messages posted to a direct message conversation from a multiparty direct message.channel_history_changed - Bulk updates were made to a channel's historymessage - A message was sent to a channelmessage.mpim - A message was posted in a multiparty direct message channel