Performing Calculations on Multiple Metrics (Counts) in Kibana 4
This looks like scripted fields as described here https://www.elastic.co/blog/kibana-4-beta-3-now-more-filtery
Kibana now includes support for Elasticsearch scripting! Not only can you write scripts, you can name them and access them like fields anywhere in the application. Create a scripted field and it becomes part of the documents you view in Kibana as if it was always there. The only catch is that since the script isn't technically part of the Elasticsearch index, you can not search scripted fields.
You can, however, use scripts to combine several fields, or perform math on number fields, and then drop the result into a visualization. To help get you started, we've added a handy link in the scripted fields screen titled “Create a few examples from your date fields." Find it by heading to the Settings tab's “Index" section. Select or create an index pattern and click the “Scripted Fields" tab.