4.2.1.5 Append Folder to Empty Group

To append new folder to the empty folder group (after you create folder group by typing m g), firstly open it, then execute append command in the next line. If it is closed, folder is appended on the same level with the folder group above. It is difficult to explain by words so try it. In other words, appended position depends on the open/close status of the upper one.