Compare between many fields?

So i was wondering if it's possible to sum-up the value contained in a given field within all docs and then compare it to another field in order to construct a pie?

A doc contain the field sales_revenues_usa and another field sales_revenues_uk and another fields sales_revenues_russia. each doc has the value for each field for a given day. what i want to achieve is summing up the values for each field and then construct a pie chart to visualise which country has which percentile?

is that possible though Kibana?

You can use a scripted field in Kibana to sum up the values (see in Settings >> index >> field >> Scripted Fields). This will create a field you can use in visualizations, alongside regular fields.