onActionProcess.js

import("system.neon");
import("system.util");
import("system.workflow");
import("Sql_lib");
import("system.vars");

var workflowId = vars.get("$field.selectedWorkflows");
var [name, processXml] = newSelect(["NAME", "PROCESSXML"])
    .from("STANDARD_WORKFLOW")
    .where("STANDARD_WORKFLOW.STANDARD_WORKFLOWID", workflowId)
    .arrayRow();

neon.download(processXml, name + ".xml");