Hi I am new to Seblod and although it looks fantastic, after watching all of the (very few) English tutorial videos online I am still fighting a losing battle. I just want a user to be presented with a dropdown list of subcategories to chose from a preset Parent category.

I have set a 'Category Parent ID' field set to hidden with the ID of the parent category id like to be always set. 

I would then like a drop down of all of the sub categories under that Parent ID so the user can select a sub category only. I have tried using an 'Article Category ID' field but it never populates with the subcategories, its just blank. 

PLease help, how can i achieve what seems like a very simple and basic task.