How to show bookmarks AND thumbnails simultaneously

@Sanchan and others...

Updating the information about this functionality.

In the "Classic" interface, it IS possible to have the Pages/Thumbnails panel open on the left and the Comments panel open on the right.

But in the new "Modern" interface, Adobe ganged both panels on the left and only one can be open at a time.

Solution:

• Revert back to the Classic Interface. For instructions, see https://community.adobe.com/t5/acrobat-discussions/acrobat-2023-how-to-revert-to-classic-gui-user-interface/m-p/14052807#M426838
• Complain directly to the engineers (and VOTE!!!) at https://acrobat.uservoice.com/forums/590923-acrobat-for-windows-and-mac/suggestions/47082691-ditch-the-2023-user-interface-in-acrobat

The new interface is not ready to be used because of insane shortcomings like this one.

Has it always been that way? I upgraded my Acrobat Pro to 2023.008.20423 and it looks completely different now. I could've sworn that I could always see the page thumbnails on the left and the comments on the right? Am I crazy? And why did  they change that if so? 

While not possible in a single window, you can open the file twice (open it once and then go to Window - New Window to open another copy of it), and have one version show the Bookmarks panel and the other the Pages panel. You can then tile the window and arrange them in such a way that both panes are visible one next to each other. Of course, this is only useful for visual reference. You will only be able to use one of them to change the actual active document, not both.