Hello Kannan,
there is not much to say around this, use in a cell following syntax for a formula:
1. UserResponse(<technical_name_of_variable>)
2. PromptSummary()
If you are not sure, then visit following interactive tutorial:
Web Intelligence 4.0: Create a formula to display a filter selectionWeb Intelligence 4.0: Create a formula to display a filter selection
Also search for those keywords in the product documentation available here:
Best regards,
Victor
http://help.sap.com/businessobject/product_guides/sbo41/en/sbo41_webi_user_guide_en.pdf