ELK-5.0 Logstash geoip filter target "geoip", unable to remove fields

Elastic Stack Logstash
1

I am currently using ELK 5.0 version
I need only few of the tags from the default "geoip" target.
But i'm unable to delete the unwanted fields.
I have tried the following settings, but none worked. I still see all the fields on the logstash pipeline.

Pasted image1125×49 2.2 KB

TIA!

2

Please don't post screenshots. Use copy/paste.

Please show an example event that isn't processed correctly. Use a stdout { codec => rubydebug } output.