Sub tags in 1password 8

I used to be able to create sub tags in 1password, and I still can, but it is not created in the same fashion. I have almost 250 entries, so I created a main tag, and the several sub tags under the main tag. The way I viewed my password would then be to click on the main tag at which point I would see the sub tags. This is not like this any more. For example if I created a/b, then when I click on the a tag, I would see b. Now I see a and b as if they are both main tags. I don’t know that b is a sub tag of a.