How do I add a custom field to my report in Tableau?

To export a custom field:

Go to the Data Sources page, select the required data source, and then select Edit.
Under the Jira Work Management tab, find Issue Custom Fields, and then select the required field.

Custom fields are located in the Issue Custom Fields table under the Jira Work Management tab. The field might be exported as a part of the Issue table or as a separate table. You can verify this by selecting Preview ERD and locating your custom field.

As for adding a field to the Jira dashboard template, you will need to customize it yourself or ask for assistance from experts. We can only help you with setting up the configuration of your data source.