You can create as many directories and sub-directories as you want in order to group the devices together. When you create sub-directories, the devices organized in it form sub-groups of a group.
A device that is unequivocally identified by its MAC address can only be stored in a single directory, i.e. only as a member of a single group.
To create a directory or sub-directory, proceed as follows:
Select a directory, e.g. Devices.
Click System>New >New Directory in the main menu bar or select the option New Directory from the context menu of the selected directory.
Enter a name for the new directory.
Click OK. The new directory will be displayed directly below the selected directory in the structure tree.
