Thread: Show sub sub categories ?

Show sub sub categories ?

Hi, i want to have sub sub categories , i know that you can do that by simply giving each category a parent , However when i go to the post an ad page it doesnt show a 3rd box of categories
example

I want it like this

Tables > No Parent
7 seater > Tables Parent
Round tables > 7 seater Parent
ect

but at the moment round tables wont load after selecting 7 seater ?

please help thanks