if you add a user to a group, you have to configure the read-view, write-view or notify-view for the group.  Or NMS will have no authority (writing, reading, being notified ) operated on the user. 

A user can be added to a group


Command Syntax
set protocols snmp v3 usm-user <text1> group <text2>

delete protocols snmp v3 usm-user <text1> group



 •<text1> the name of the user

 •<text2> the name of the group



 •This example adds user1 to group1

admin@XorPlus# set protocols snmp v3 usm-user user1 group group1 
admin@XorPlus# commit