Currently, the home page has just one level. If I click any category, it takes me directly to the article view, where all sub-categories and articles are listed in the left panel. I request two or more levels on the home page, like Category -> Sub-category. And only when I click on an article should it open the article view, with all articles listed in the left panel.

For example, if you see the Google support center (https://support.google.com/), the first level is all categories, and if I click on any category (Google Chrome), it shows all sub-categories and articles within it. Only when I click on any article does it open the article view.