Kibana has a concept of "scripted fields". These are fields that are calculated dynamically, and you can use them in visualizations just like any other fields. Check out the docs here: https://www.elastic.co/guide/en/kibana/current/scripted-fields.html
One thing you can't do though is query these scripted fields. If you want to do that, you will have to use a
script query. For example, the following query will match all docs for which (indexing_delete_time_in_millis / indexing_delete_total) is larger than 1.0:
"inline": "doc['indexing_delete_time_in_millis'].value / doc['indexing_delete_total'].value > 1",
Be careful with script queries though. They are computationally expensive and can result in errors (for example for document in which the indexing_delete_time_in_millis and indexing_delete_total do not exist, or for documents for which indexing_delete_total is 0.0).
A better way to solve this is to add the actual
delete_time_per_ document field to your documents when you index those.