Scripted feild in kibana

Hello guys , we are using kibana (7.1) i want to create a scripted field for renaming a column and computing two columns to calculate percentage in scripted field if possible
could you guide me with simple expressions.

Hi there, to clarify, are you using a script field to rename a field during reindex or are you using scripted fields to derive values from other fields?

In terms of the latter, please see these docs on scripted fields in Kibana. For example, a scripted field that calculates a percentage value based on two fields would look like this:

doc['numerator'].value / doc['denominator'].value * 100