I am not aware of a mechanism to do this using prompts in WRS.
There are a couple alternatives.
1. You could create a group-by for your report and allow the user to select the value on the left side of the report viewing screen.
2. You could create a separate section for each previously prompted value and the user could choose which section to view.
However both of the prior options only work well when replacing 1 prompt.
Another completely different approach is to create a custom SAS Stored Process with the prompts (created in HTML code via DATA _NULL_ put statements) on the left and the report on the right.