First...I'd like to clarify the difference between a face and a limit surface...A face is part of the control cage that defines a Subd. You cannot hide any single parts of the control cage (vertexes, edges or faces), either all control elements are ON or OFF. So the answer to you question is that it is not possible to hide a face of a Subd, however it is possible to achieve what you require.
The Subd is represented in Alias by a node, that node contains all the limit surfaces that make up the Subd. The display (visible or invisible) can be controlled in a few ways in Alias. You could assign the limit surfaces that you do not want shown to a new layer, then make that layer invisible. Alternatively you could use the object display->template command. Lastly, you could make the limit surfaces that you choose not to see invisible...my recommendation would be to use layers (maybe name the layer inv_surface)...that is that is the most flexible method in my opinion.
