Issues with regex in Kibana
So I don't exactly have the answer on how to make Lucene work with Regexp search in Kibana. But I figured out a way to do this in Kibana.
Solution is to use Filter with custom DSL
Here is an example of what to put in Query JSON -
{ "regexp": { "req.url.keyword": "/question/[0-9]+/answer" }}
Example Url I have in my data - /questions/432142/answer
Additional to this, you can write more filters using Kibana search (Lucene syntax)
It does the appropriate search, no escaping issue or any such thing.
Hope it helps.