When you create or edit a view Filter we can apply a Filter to the list of categories based on discipline.
Filtering the list of categories has a direct impact on the Filter Rules > Filter by: list too. If you tell Revit to only show you Architecture categories then you'll find the available parameters listed in the Filter by: criteria drop down will not include parameters that are related to other disciplines. For example, if you were hoping to use the filter to alter the way MEP elements look when they are linked into your model then you might be confused until you realize that earlier you told Revit to only show you Architectural stuff.
Remember the Filter's Filter. Same thing can happen in the View Templates, Visibility/Graphics dialog and Object Styles dialogs.