The Discussions tab will include all past discussion threads that belong to this group. To initiate a post to your group, go to the Discussions Tab > Post New Discussion.
There are several ways to post a discussion including the widget on the homepage, Post a discussion in your profile or in a group page and via email.
To find the email for your group, go to the group page and select Email Group.
Also, you can post a discussion from the email digest you receive from your community.
From your digest click Post a New Discussion, this will open a Compose New Message window in your email client, enter your subject line and content like a regular email and click send. This will post a brand new discussion in the group.
From the email digest, you can also Reply to Group to create a reply under the discussion you are reading. Or you can Reply Privately to the author of the post, all from your email client.
If you have moderator permissions, you may be asked to approve each post as members contribute to the group. This is simply a way to ensure the things being posted in the community are of value and not against the rules. Use different strategies to get members interacting and replying to the discussions. People respond differently, so make sure everyone is getting the most out of the community.