Accordion databind to sitemap (three levels accordion menu)

 I can not implement the three levels, my menu has the following schema


Item A
     Item A.1
        Item A.1.1
        Item A.1.2
      Item A.2
        Item A.2.1
        Item A.2.2
Item B
      Item B.1
        Item B.1.1
        Item B.1.2
      Item B.2
        Item B.2.1
        Item B.2.2

Item C
     Item C.1
        Item C.1.1
        Item C.1.2
      Item C.2
        Item C.2.1
        Item C.2.2

and I have implemented a sitemap AspNetSqlSiteMapProvider to recover, I'm desperate, took several days, and I'm a beginner, thanks in advance for any help