Easiest way to achive your goal is to install zgoo and try to figure out which is the head control of the tabs.
type /zgoo mouse while you are on any filter button and have a look at his parent
Should be something like ZO_PlayerInventoryFilterTab or so
now have a look at the wiki example to dynamicly adding some controls to another.
That should be enough to make it. if you need a complete soloutin and dont want to learn from it (i totally advice! you to do it by yourself), reply on my post and wait until i got time for it *lol*
Cheers