how add relation between two business objects in stimulsoft report

Question

I have two class

public class PrintMoredKhesarat
{
    public decimal ID { get; set; }
    public string BimeGozarName { get; set; }
    public string BimeShodeName { get; set; }
    public string PRVNO { get; set; }
    public string HVNO { get; set; }
    public string MablaghElamShodeKhesarat { get; set; }
    public string MablaghKolKosorat { get; set; }
    public string MablaghTakhfif { get; set; }
    public string MablaghKhesaratPardakhtShode { get; set; }
}

And

public class PrintKosorat
{
    public decimal MoredKhesaratID { get; set; }
    public string ItemKosorat { get; set; }
    public string MablaghKosorat { get; set; }
    public string Sharh { get; set; }
}

I'm rebuild and add dll to business objects.two class is master - detail.
I want add relation between two business objects.but ParentDataSource and ChildDataSource is empty.

How add relation between two business objects in stimulsoft report?