Tekstiä jiihaa
If you have category plants for example and subcategories trees and bushes and posts with parent and child categories applied, after clicking on plants filter it will display posts with category plants and subfilters with back button, after clicking on subcategory trees for example it will show posts from this child category, but make sure that parent category is applied to child category posts as well if you want them to be visible in parent filter like in the screenshot:
