In order for api.pov.GetCurrencyIdForEntityParentCons or api.pov.Parent.MemberId to work, you have to make sure the cube view is displaying valid parent/child combinations. You will likely need to change how your cube view is setup if you want to display consolidation type information like parent currency (since this info is parent/child specific).
I have set up several reports in the past that use dynamic calculations to return consolidation information like this. Those reports typically have the entity dimension in the rows and uses some type of '.Tree' expansion function.
