As a Google Group manager, click Posting policies from Group Settings.
Click Allow Email Posting and Allow web posting.
Turn on Conversation history.
Set who you would like to reply privately to authors (Group members or Managers). Accounts that send messages to the Group are known as Authors. Save your changes.
From the Group's Conversational View click to open a message.
From the message, click the 3 vertical dots, select Reply to author.