Showing only certain categories

Hello,

I created one main portfolio category and few portfolio items and marked them as subcategories of that main category. I created page with portfolio grid and set it to show portfolio items from main category.

Product types (main category)
– type1 (sub)
– type2 (sub)
– type3 (sub)

That page shows those subcategories OK.

Then I created more categories, which are subcategories of subcategories.

Product types (main category)
– type1 (sub)
– a
– b
– c
– type2 (sub)
– type3 (sub)

Now my page which is only supposed to show main categories, instead shows all categories, items from main and subitems of items from main.

How to solve this?

Thanks