Subreport with stored procedure and additional parameters

I have a Crystal report in which the main page has 1 parameter 'Param1'. There is a subreport in report header which has data source as stored procedure (having 1 input parameter). In the main report via 'Change subreport links', I have linked parameter Param1 of the main report with the input parameter of the subreport.

When I execute the report I get parameter selection screen for 'Param1'. Upon selecting the values, the stored procedure in sub report gets executed successfully with input parameter=Param1. Now, I want to define 2 more parameters in sub report and want them to be presented to the user. Data which is returned by the stored procedure should be filtered on the basis of the 2 parameters selected in the subreport. Is this possible?