How to write script for DATE Range

HI ALL,

             I am new to SAP BO Design Studio, i have five filters Start Date , end date, Plan, profit center material and . Source for application is BW. how to define start date and end date filters. the no of plants and ohter filters should display for next filter should display, in between the start date and end date.

How to define date range filters...

Thanks,

Ramana