This is a class event and filter event hook. When used with a system event, Workflow based logic is inserted immediately before a WorkView filter is executed. This can be used in conjunction with the Set Filter Options action to add additional constraints and sorting to the filter before it is executed. When this is configured as a class event, this event applies to all filters for the specific class. When this is configured as a filter event, it is applicable to a specific filter.
When executing the OnBeforeExecuteFilter constraint, the fixed constraint for the filter will be resolved first (including resolving any macros). Then the OnBeforeExecuteFilter event executes the configured logic. In this logic, the user can specify additional constraints to be added to the ones that already exists via the Set Filter Option Workflow action.