Go to Apps → Issue Picker Custom Fields Manager
Create your new custom field from create button
Choose the name and layout of your brand new custom field
Your new issue picker custom field you will be able to edit the field and set the values from issue view
You can edit the value from the pencil icon located in the upper right part of the field. And it save value when lost the focus.
This is how you can see the new issue picker field in Jira issue view
You can also add a new column in issue navigator to display the issue picker custom field
You can even use the custom field searcher to create filters using the newly created issue picker custom field
Just add the criteria on that field and complete the form to filter the results
