For Quick introduction to Groups and subgroups
To create a group, Right-click on the Home icon and click on Add
A new window will open. Give the name of the group and then click OK.The new Group will be created
To know more about restricted groups CLICK HERE
In a similar way, you can create the subgroups, Right click on the group you just created Eg. 1 June and add subgroups like we have added 1,2,3