If you would like to add a block to your Group or Events home pages that displays the latest forum posts , or maybe add a block to the home page for your site, you will need to do the following.
Builders > Pages Blocks > Groups Home
or Main Events Page for the events page
or Homepage for the index page
Drag an RSS block to the required position.
Give it a name - perhaps 'Latest group forum posts'
Now add the following for the URL
Be sure to replace yoursite.com with the URL for your site
(if you want to display the events feed instead - simply replace 'groups' with 'events')
PS. if you want to display the latest groups forum posts on each individual groups home page - you will need the following free modification