What do you mean when you say that you want to extract one of the columns? You want to extract it as an Attribute in your FlowFile or? If yes, you can use an ExtractText processor for example, where you add a new property (using the + sign ) and you define your extraction rule, like a Regex. As you are using a csv file, I think the following example suits your use case perfectly: https://community.cloudera.com/t5/Support-Questions/How-to-ExtractText-from-flow-file-using-Nifi-Pro...