How to make a secondary checkbox appear after the main checkbox is selected?

Question

css

Good afternoon!
there is such a page with a fitness.ad-rocket.com.ua/schedule class schedule .
The Events Schedule WP Plugin was used for the schedule ( link )
In the schedule, there are categories and subcategories of activities, I want to make the subcategories appear only after the main category is selected.

For example, on the fitness.ad-rocket.com.ua/schedule
page there are Pilates classes, this is the main category.
And pilates parent is a subcategory.

How to make pilates parent appear only when Pilates is selected?

Answer 1

We put the hide class on the parent, write to it.hide {display:none;}

$('#some_select_id').on('change',function(){
$('#some_parent_select_id').removeClass('hide');
});