We created an OnlyBreadCrumbMVCSiteMapNodeAttribute. We decorate any code we want the attribute
public class OnlyBreadCrumbMvcSiteMapNodeAttribute : MvcSiteMapNodeAttribute
{
    public OnlyBreadCrumbMvcSiteMapNodeAttribute(string title, string parentKey)
    {
        Title = title;
        ParentKey = parentKey;
        VisibilityProvider = typeof(BreadCrumbOnlyVisibilityProvider).AssemblyQualifiedName;
    }
    public OnlyBreadCrumbMvcSiteMapNodeAttribute(string title, string parentKey, string key)
    {
        Title = title;
        Key = key;
        ParentKey = parentKey;
        VisibilityProvider = typeof(BreadCrumbOnlyVisibilityProvider).AssemblyQualifiedName;
    }
}
Also have a visibilty provider
public class BreadCrumbOnlyVisibilityProvider : ISiteMapNodeVisibilityProvider
{
    public bool IsVisible(SiteMapNode node, HttpContext context, IDictionary<string, object> sourceMetadata)
    {
        if (sourceMetadata["HtmlHelper"] == null || (string)sourceMetadata["HtmlHelper"] == "MvcSiteMapProvider.Web.Html.SiteMapPathHelper")
        {
            return true;
        }
        return false;
    }
}
Use like
    [OnlyBreadCrumbMvcSiteMapNode("Upload Documents", "AssetDocuments")]
    public virtual ActionResult FileUpload(int assetId)
Upload Documents will be breadcrumb title. AssetDocuments is the Parent Key
If you pass the 3rd parameter, that sets a key of the breadcrumb node itself