I'm slightly OCD when it comes to organising my settings in Orchard, of which I seem to have a vast amount. And luckily, Orchard has a nifty way of doing this for you and it is beautifully simple to implement.

So to start with you are going to need to have some site settings, which I have covered in this post. Once you have built your site setting, you are going to need to create a menu item that will be displayed in an expandable list under the Settings menu item in the Orchard dashboard, which will be done in the handler.

public class UniTownSiteSettingsPartHandler : ContentHandler
{
 public UniTownSiteSettingsPartHandler(IRepository<UniTownSiteSettingsPartRecord> repository)
 {
  Filters.Add(StorageFilter.For(repository));
  Filters.Add(new ActivatingFilter<UniTownSiteSettingsPart>("Site"));

  T = NullLocalizer.Instance;
 }

 public Localizer T { get; set; }

 protected override void GetItemMetadata(GetContentItemMetadataContext context)
 {
  if (context.ContentItem.ContentType != "Site")
   return;
  base.GetItemMetadata(context);
  context.Metadata.EditorGroupInfo.Add(new GroupInfo(T("Statistics")));
 }
}

The important method here is GetItemMetadata, which I have used to add a new group "Statistics. Next you need to actually place your site settings into that group via the Editor method in your driver.

protected override DriverResult Editor(UniTownSiteSettingsPart part, dynamic shapeHelper)
{
 return ContentShape("Parts_UniTownSiteSettingsPart",
  () => shapeHelper.EditorTemplate(TemplateName: TemplateName,
   Model: part,
   Prefix: Prefix))
  .OnGroup("Statistics");
}

So all we are doing is appending .OnGroup("Statistics") to our return statement. Simple!