If you wish to stop seeing posts from a particular group on your homepage or edit the group list in your navigation bar, you can fully customize the list of groups that you're following. To get started, just follow these steps:
In the "Account" menu at the top, click "Manage Groups."
On the next page you will see a list of the groups that you're following.
If you hover over any "Following" button below group on the list it will become an "Unfollow" button.
Click the "Unfollow" button on any group to remove this group from the list of groups you're following and stop seeing its posts on your homepage. Its button will change to “Follow” when you have successfully unfollowed it.
You may also click and drag the square button to the right of the "Following" button to rearrange their order your navigation menu and elsewhere on the site.