Use Prompt Selection in multiple columns

Summary:

In a report, we would like to have in Prompt in Column A that allows a user to select multiple members to display on the report for Column A. In subsequent columns, we need the same set of members to display without having to prompt again. In other words, we want to dynamically use the exact same members selected in the Prompt in Column A in columns B,C, etc as needed. I don't see a member selection formula equivalent to "Use Members in Column" available. The only way we can currently get this to work is to set up a