I have two flow file: 1) $.category = sport 2) $.temp_array = "music" , "sport" , "traveling" I just want to check $.category is exist in $.temp_array or not using in expression language. Ex. ${category:in(${temp_array})} But it doesn't work with array or (variable). I have used this login on RouteOnAttribute processor. Instead of above example if i write like this: ${category:in("music","sport","traveling")} then ii will give you perfect output But this is static data. Instead of this i want to use dynamic. Please help. ... View more