Hello Alexbogoslav,
You have done nothing wrong.
<blockquote>-CagegoryA
–SubcategoryA
—SubsubcategoryA
—SubsubcategoryB
—SubsubcategoryC</blockquote>
is how JA K2 Filter fetches category. If the sub category is chosen, then the parent category will be automatically chosen. This construction will make sure all categories display right following the tree format.
When filter, if you only want to fetch item on sub categories, for example: SubsubcategoryA, SubsubcategoryB, SubsubcategoryC, not from CategoryA, SubcategoryA, then in JA K2 Filter Module, set “Fetch items from child category” as No.