description of polymorphic object filter

This screenshot of a rule set's layout editor shows the filter dialog for a polymorphic object in the Fields palette.

In this image of the filter dialog, one of the pre-defined sub-types has been selected and appears in the dialog's text field. The filter dialog contains:

• the name of the polymorphic object and discriminator field,
• a text field for selecting the discriminator sub-type,
• a Cancel button to close the dialog, and
• a Filter button to filter the sub-fields according to the selected sub-type.