Why dont u tried from expression?
Anyway, try this
If(Aggr(count({<[Event Type]={'Non Deal Management','Conference','Field Visit','Field Trip','Other GCA','IMG - Investor Reverse Inquiry'}>} distinct [Meeting Id]),[Client name]), [Client name])
Best Anil, When applicable please mark the correct/appropriate replies as "solution" (you can mark up to 3 "solutions". Please LIKE threads if the provided solution is helpful
