public ProductItemCollection Items {get; set;}

class BOMConfigurator
{
   private Dynamicweb.Rendering.Template template;
   private ProductCollection BOMProducts;
   private ProductItemCollection Configurators;
   private Product product;
 
   public void SplitBOM()
   {
       //### Split BOM items from configurators
       BOMProducts = new ProductCollection();
       Configurators = new ProductItemCollection();
       product = new Product();
       template = new Template();
 
       if (template.LoopExists("BOMConfigurators") || template.LoopExists("BOMProducts")) {
           foreach (ProductItem item in product.Items)
           {
               if (item.BomGroupID == string.Empty) {
                   BOMProducts.Add(item.Products[0]);
               }
               else {
                   Configurators.Add(item);
               }
           }
       }
    }
}