Member selection restriction in run time prompt

We have run time prompts for Scenario, version and Entity for a business rule. When I select the Actual scenario in RTP for scenario, I dont see the alternate hierarchy within Entity for selection for Entity RTP and see only the main hierarchy. But I do see the alternate hierarchy along with primary hierarchy for Entity when I select Plan or forecast scenario in RPT for scenario. How do I make the alternate hierarchy available for selection for entity when selecting the Actual scenario. I checked the variable designer and there is no limit set for Entity variable. Thanks