Displaying an image thumbnail in CMSB
If I'm understanding correctly, that should be pretty easy for a multi record section.
Go to Section Editors under the CMS Setup menu
Click on modify for the Banner Advertisement editor
Add your image field name (not the Field Label) followed by a comma in the ListPage Fields where you want to see the image thumbnail.
Save the details and you should see the thumbnail where you indicated in the attachment
Caveat: You'll only see one image. Either the single uploaded image or the first image if there are multiple images uploaded.
Hope that helps,
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