Filter builder and WMS layers

I do not have any experience in configuring the Silverlight viewer (or Essentials) to use the Filter builder.  I am trying to use WMS layers in my Essentials Map and have these layers accessible to the filter builder.  The filter builder does not seem to recognize WMS layers--it definitely Does recogize ArcGIS Server Services.

 

Does anyone know of how to get the standsard Filter builder tool in Silverlight to recognize WMS layers?

 

Thanks,

 

Michael