Widgets are a bit different from web parts in terms of macro resolving.
To get the value of a property of the current web part, use only: {% PropertyFieldName %}
{% WebPart.GetValue("WebPartControlID","PropertyFieldName") |(identity)GlobalAdministrator%} - it will easily resolve for current instance.
but for widget if we take (static html) I think you need to call MacroResolver.Resolve(Eval("FieldName").ToString())
in the code behind.