Extra drop down menus

Hello,

I am looking into expanding some Dropdowns that we currently have and I am looking to add more levels to them.
The dopdowns that I am interested in are the ones that are defined in Quote/Sync > Products and used in Sales/Quote
It should look similar to the ones in the screenshot bellow.

I am wondering if anyone managed such a change to SuperOffice Online, and how it was done, Script, Addons?
Would this be possible without altering the base program?