Just thinking out loud here... how is a multi-threaded export going to work? Halving multiple threads writing to the same file sounds like a bad idea to me. Please keep in mind that I haven't tried this at all, ymmv.
I am not familiar with this notation MATCH (nod**:$__{node}**). I highlited the confusing part. What are you trying to achieve here?
apoc.periodic.iterate requires two cypher statements, one to get the data, and one to operate one the data. I only see one cypher statement in your query.
I agree with @ThomasVarias, this doesn’t seem to make sense. You did remove the parallel execution, but now it will probably just overwrite the existing export and create a new one. You probably would need to append a unique identifier to the end of the file name so a new file is created each time. Are you intending to generate the export across multiple files? Have you tried exporting the data directly without the periodic iterate?
Yes i have tried it works well. I need to migrate data from neo4j to mongoDB. And it is one time process. Is it the right way i am doing saving data in CSV file and then do the further process or something else i can try to migrate data.