I think the problem above is that nginx.access.remote_ip is only available after the ingest processor. The processing of the log line happens in Elasticsearch, so filebeat cannot filter based on this field as it never sees it.
For your case you would either have to do this in the ingest pipeline or do a regexp on the filebeat side with exclude_line: https://www.elastic.co/guide/en/beats/filebeat/6.5/filebeat-input-log.html#filebeat-input-log-exclude-lines