Cascading Droplists for Add/Edit form

I want a cascading set of 2 droplist for categories. The first select list will has options of categories table with parentid=0 and “Select category” selected. The 2nd list will be hidden. When the user selects a category from list one, the list two will becomes visible and populated with categories having parented= the id of the selected category. This is for add form. For edit form I want giving a category id to preselect list one and list two with that value. I'm attaching dataschema with some values and HTML template. jQuery / Bootstrap / PHP 7