sonata add more field in user bundle admin

Question

i'm a noob of sonata, i'm loooking for extends user field list of admin bundle, i try various solution founded but i can't resolve my problem.

i already extends userAdmin class:

        contexts: [admin]
fos_user:
    db_driver:      orm # can be orm or odm
    firewall_name:  main
    user_class:     Application\Sonata\UserBundle\Entity\User


    group:
        group_class:   Application\Sonata\UserBundle\Entity\Group
        group_manager: sonata.user.orm.group_manager                    # If you're using doctrine orm (use sonata.user.mongodb.group_manager for mongodb)

    service:
        user_manager: sonata.user.orm.user_manager                      # If you're using doctrine orm (use sonata.user.mongodb.user_manager for mongodb)

sonata_user:
  admin:
    user:
      class:      Ap\UserBundle\Admin\Model\UserAdmin
    group:
      class:      Ap\UserBundle\Admin\Model\GroupAdmin

but i imagine that i must extends BaseUser entity, is right?

ps. i use symfony 2.8 version

thank you