If we understood you correctly, you want to import data from MySQL with Devart Excel Add-ins, but cannot find the "Merge Fields Detection Behavior" in the MySQL connection editor. Only MailChimp connections have such parameters. Data are selected from MySQL in the same form as they are stored there. If you didn't transfer the merge tag information when migrating MailChimp data to MySQL, you won't be able to import it to Excel from MySQL via Excel Add-ins.
You can use Skyvia, our online solution for data integration, backup, and management (
https://skyvia.com/ ), to replicate data from MailChimp to MySQL. In the MailChimp connection editor select "Join All Merge Fields" in the "Merge Fields Behavior" list. Replication will create MySQL tables, corresponding to the replicated MailChimp objects. The created ListMembers table will have columns, corresponding to all Merge tags, and when you import its data from MySQL via Excel Add-ins, all the merge tags will be available. For more information about how to create Replicate package in Skyvia, please refer to
https://skyvia.com/resources/docs/index ... ackage.htm
https://skyvia.com/resources/docs/index ... n_task.htm