Logstash: Custom filter, Can we access members/columns/fields of another filter in a custom filter?

Elastic Stack Logstash
1

I am creating my own filter, as I am uploading a CSV file and I need to access fields in CSV in my custom filter.
Is it possible to access those fields in my filter?

2

This is a duplicate of Logstash Custom Filter: How to access, fields of csv being uploaded in a custom filter.