How to let users store custom input and then reuse it?

[Pavel]

According to the business requirements, users need to enter customers info in a custom field. It must be reusable - next time when users want to handle a particular customer they had before, they just select it from a cascade list.

Unfortunately, can't find a way how to configure it using regular Jira tools. Any suggestions please?

[Nic Brough -Adaptavist-]

Welcome to the Community!

Jira doesn't have support for arbitrary data that's outside the issue.  Some people will co-opt issues in projects to do this sort of thing (in your case, it would be having a project where each issue representes a customer and has fields to capture data about them)

The other option is to look for an app that can support your data, there's a number in the marketplace.