HTML Widgets; widget.UI.DocumentManagerComboBox; does not handle files in sub-folder correctly

The Document Manager supports a single level of sub-folders, e.g., a Client's Document Manager folder might contain a folder called "/Identification" which contains documentation and images regarding Identification Items recorded for the Client.

The Document Manager Combo Box used in Widgets such as Client Identification and Client Edit, did not support this sub-folder correctly. All files were listed but with the sub-folder removed which resulted in the preview (for images) not working correctly.