How to write kql query in kibana to include only 9 characters of a field?

I am using kibana 8.1 so I want to filter the data in discover section. Tha index has a field whic is in number format and it has different kinds of numbers which range from 4 characters up to 12 or 13 characters. So I want to show me only the data which are 9 or above 9 characters in that specific field. The field name is for example phone_number.

Hi @Arifullah ,

if the field is numeric I think you might leverage Kibana filters for this use case:

If your field is keyword based, you might leverage runtime fields to create a new field with only values which have a length of 9, and return null otherwise.

Hi @Marco_Liberati
there is no field by the name of byte in my index. The field which I want to filter is phone_number and it's type is long

Hi @Arifullah ,

you can configure the filter with your field name, but the same logic should apply.

Thank you @Marco_Liberati your answer solved my problem.

@Marco_Liberati I have also another question if you can help me I shal be very thankfull.
There is also field by the name date but the data of that field is not in a proper date format its only a number. So I want a filter to include only the data of max date field I mean how to create a filter which finds the maximum value of the date field and filter the index based upon that value.