Define prompts on BEx query in universe

Universe is based on BEx query.

I have three objects: Calendar Day (Start Date and End Date) as Prompt, Plant and Material.
Following are the prompts:

Enter Calendar Start Date:
Enter Calendar End Date:

Enter Plant:

Enter Material:

Now, lets select Start Date as 01/12/2013 and End date as 16/12/2013.

Select Plant As Tremely Inc.

Depending on the above two values, how do I define Material so that it is filtered and it should show the Material values which correspond to the Tremely Plant and Start Date and End Date .

Thanks,

Antara Das