In order to create a document folder for your group, go to your group and click on the ‘Documents’ tab.
Click on create new folder, and give it a title.
To upload a document, click on the ‘Upload Files’ button, then drag and drop a file. When uploading a file, the system creates a post for your group activity feed. You can write something about the document for the post.
Remember: the visibility of your documents depends on your group’s settings. To change the settings, go the tab ‘manage’ and select between public, private, or hidden.