If you are on Facebook's new UI, the following are the steps on how to connect a Facebook Group to Zoho Social.
1. Go to the Social Channels section under Zoho Social's Settings,
2. Click on Connect button beside Facebook Group
3. On the pop-up window, select the Group you want to add, that's linked to your Facebook Account
4. Click on Authorize Zoho Social on Facebook
5. You'll be redirected to Facebook. There, under your Group's settings, scroll down to Advanced Settings, where you'll find Apps.
6. You'll be taken to the Group apps menu, where you have to search for Zoho Social and click on Zoho Social in the results.
6. Confirm that you want to add Zoho Social as an App to your group by clicking on Add button on the pop-up.
7. Done! Go back to Zoho Social and your Facebook Group will be ready!