Arjan
Named Queries define persistent subsets of the data accesible from any View's subset menu. If you set a View subset to be a Named Query, you will always see just the pre-defined subset according to the definition of the Named Query, regardless of subsequent filtering. If you want your users to be able to do further Sidebar filtering starting from a Named Query subset, set the View subset to be 'intersected with' the Named Query. This means that the view will inially show the Named Query subset, but further filtering actions can be applied and remembered on the tab.

Use the Humans Resources demo, which has many Named Queries (and a Venn View) to experiment with 'intersected with' behavior.