Hi,

Maybye you could reuse this snippet. It allows you to change the root for the ContentReferences property editor dialog window.

    public class ProductPage : StandardPage
    {
...
        [Display(Name = "Content References list", GroupName = SystemTabNames.Content, Order = 1000)]
        [CustomContentReferencesRoot]
        public virtual IList<ContentReference> TestContentReferences { get; set; }
...		
    }

    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]
    public class CustomContentReferencesRootAttribute : Attribute, IMetadataAware
    {
        public void OnMetadataCreated(ModelMetadata metadata)
        {
            ExtendedMetadata extendedMetadata = metadata as ExtendedMetadata;
            if (extendedMetadata == null)
                return;
            extendedMetadata.EditorConfiguration["roots"] = new[] { ContentReference.StartPage.ID, 44, 45 }; // set roots id here based on custom logic
        }
    }