Users can move content to different groups or out of any group when this function is enabled.
This function makes creating content a lot easier since authors don't have to worry if they place content in the wrong location. They can always correct it.
Users can only move content to groups they are part of. If you as a SM want to move content from a member to a different group, the member should also be part of the new group. (content can only be moved to a group the author is member of)
Besides, when users create content via the '+' button, they can also specify which group the content should belong to. This also makes creating content much easier.