Hiearchy function creates duplicates

[#1]

Hi Team,

            Need help I am having below date which is creating duplicates while creating hierarchy using hierarchy function. Please help me to resolve the issue

Nodetype: Country-> State->City

NodeID  ParentNodeID Nodename  Parentnodename nodetype

1             11                   one               Eleven               City

11            12                  Eleven          Twelve               City

11            13                  Eleven          Thirteen             State

12            14                  Twelve        Fourteen              State

13            15                  Thirteen      Fifteen                  Country

14            15                  Fourteen     Fifteen                 State