I have a rendering based on a data source. One of the fields on the data source is a DropLink. I added a Custom Experience Editor Button to the rendering to edit the DropLink. The field I want to edit is called Theme:
When specifying fields for the
Field Editor Button type button, make sure the Fields you specify are using the Item Name instead of the Display Name.
Additionally, you must make sure that field that you are specifying in the
Fields field, maps directly to the same field in the data that's being displayed by your rendering.
I covered this and other topics related to creating
Field Editor Buttons in Sitecore in my video: https://www.youtube.com/watch?v=D6jqqaBMu0s&t=25s