I agree with Gicu that what you're seeing is coded command bars. The explanation is right in the page of the link he provided:
When you open a previous version Access database and you choose to display the ribbon, custom toolbars appear as groups on the
Add-Ins tab. Each group in the tab corresponds to a custom toolbar, and each group uses the name assigned to the original toolbar. However, the toolbars must be visible in the legacy database or they do not appear on the tab.
If you have access to the code, open a module and look for code that uses the word CommandBar or CommandBars
I don't understand the original question. What is it you want to do, add a menu or menu item to what you've shown? If so, I think you'd have to find the code that creates one example of what you need and then add code to create that.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.