Network groups are used in policies "by reference." A change to a network group definition changes that definition in every policy that uses (references) the network group.
If the network group is being used by any published policies, you will be asked if you want to update devices in the field immediately. Because network groups are shared across policies, make sure you know what policies any network group changes will affect.
Find the network group in the list that you want to edit, and then click the corresponding View button
in the right column. (The buttons in the right column appear when you hover the mouse pointer over the row.)
The Save button is not active if you have not entered any SIDs, NIDs, MCCs, or MNCs or if you have invalid ones entered and they are not corrected or cleared.