Am not sure whether winforms supports nested property binding, I guess it doesn't. but you can always add proxy properties like this.
public class CustomerLanguage : IDbIdentity
{
public Guid Id { get; set; }
public virtual DocumentLanguage DocumentLanguage { get; set; }
public string Name { get { return DocumentLanguage.Name; } }
}
public List<CustomerLanguage> CurrentCustomerLanguageList
{
get { return _currentCustomerLanguageList; }
set
{
_currentCustomerLanguageList = value;
bsCustomerLanguages.DataSource = value;
cbLanguage.DataSource = bsCustomerLanguages.DataSource;
cbLanguage.DisplayMember = "Name";//Just name
cbLanguage.ValueMember = "Id";
}
}