How to use dependent parameter in WEBI BO 4.2

I am using SAP BO 4.2 and have built a WEBI that is based on a SAP HANA Calculation View. In this HANA view i am using a combination of input parameters and variables. The 2 input parameter that i am using are required. Each of the variables has an associated list of values that are based on scripted views. In SAP HANA Studio, at run time i am able to enter values into my view required input parameters and then the variables list of values use the values that i entered in my required parameters to display the variable list of values. In WEBI, this functionality is not working. When I enter the values in the required parameters at run time those values are not being passed to the variable parameters list of values. Basically, my requirement is to have WEBI optional parameters that are dependent on the WEBI required parameters so that once i enter the values on the required WEBI parameters the optional parameters use these values to derive the list of values.

Is this requirement possible in WEBI BO 4.2 and if so what is the best approach on accomplishing this requirement ?