Verify that a user belongs to an LDAP + PHP group

I would like to know if it is possible to check directly in the AD, if a user belongs to a particular group, to validate it as admin or not.

I'm doing it this way:

    /*
    * $this->status status da conexão
    * $this->ds identificador do link
    * $this->dn DN base
    * $this->usuario = usuário que busco no grupo
    */

    public function isAdmGroup() {

    if ($this->status) { 
        $grupo = 'CN=GrupoX,OU=Grupos,OU=Grupos de Acesso,DC=exemplo,DC=com,DC=br';
        $filter = "(&(objectClass=user)(sAMAccountname=".$this->usuario.")(memberOf=".$grupo."))";
        $attributes = array('memberof');
        $search = ldap_search($this->ds, $this->dn, $filter, $attributes);
        return ldap_get_entries($this->ds, $search);
    }
}

However, it returns all user groups, and sometimes it's a large array.

I'd like to do a more objective search, just checking whether it's part of the group or not, instead of returning all the groups the user belongs to.