get distinct region/campaign pairs only when requested indicator exists
get distinct region/campaign pairs only when requested indicator exists

unicef/rhizome,unicef/rhizome,unicef/rhizome,unicef/polio,SeedScientific/polio,unicef/polio,unicef/polio,SeedScientific/polio,unicef/rhizome,SeedScientific/polio,unicef/polio,SeedScientific/polio,SeedScientific/polio