In this sample application, query panel displays an 'Employment Date' field (which is a transient attribute) and the value keyed in for this field is mapped to a bind variable. This bind variable can be used by the Criteria Items to form the required 'where clause', based on the use case requirement. Please note that, 'display property' of Criteria Item can be controlled from the UI Hints tab (UI Hints tab -> Rendered Mode-> All/Basic/Advance/Never). In the attached sample application, first two criteria items are not displayed to the user, but the actual query is getting generated basen on these two items only.
SELECT .... FROM JOB_HISTORY JobHistory WHERE ( ( (JobHistory.START_DATE < :bndVarEmplDate ) AND (JobHistory.END_DATE > :bndVarEmplDate ) ) )
[Runs with Oracle JDeveloper 11g R1 PS1 + HR Schema]