Group Mode doesn't seem to work

Using the tutorial at Step 6: End of Part One. When I select Part 2: Organisation, the group mode control is supposed to show nothing is selected, but it does not and when I go to document and try select group it is grayed out and cannot be selected to de-select the group. I hope I am understanding how this is supposed to work, but doesn’t. I’m not sure how important this is, but I can’t make it work so I’m not sure what it’s supposed to do.