Folder thumbnail gallery

The first picture is my Devonthink 2 version. When I select the folder, the pdf files which are in that folder are appearing with the first-page thumbnail, like thumbnail gallery. This mechanism was perfect for me.
However, after I update to Devonthink 3, I can’t see the folder thumbnail gallery as I could see in version 2. How can I make the “No Selection” part in the second picture (dark mode) show the thumbnail gallery?

There’s a hidden preference

Copy this link and open it in Safari



Thank you for your reply.
However, it was possible in DT 2 as you can see on the white picture. Do I need to change some setting for the preview pane?

Yes …

Thank you. I made it by the link you gave.