Thanks for the clarification.
You can definitely organize your items in folders to represent which shelves they are stored on as you described but, in order to make your folder designations visible on the Listings pages (including Active and Closed), you would need to create your folders from under the “Listings” tab.
If you were to create folders from within the Inventory section, they would only be visible on the Inventory Management page, which you can reach by mousing over the “eBay Sales” tab within your account and selecting the “Manage Items” option under “Inventory”.
I will also share your comments in this regard with our Product Management team for consideration. We appreciate the feedback!