You can filter those out this way: https://www.advancedcustomfields.com/resources/acf-fields-taxonomy-wp_list_categories/
So the next thing to do is to listen for a change on the checkbox and then show the div you just hid. Then you’ll either need to fetch the children of those selected, or, if possible, hide the checkboxes.
If there’s a way to customize the HTML that ACF spits out on that form, then you could add a class or data attribute with the id of its parent (this is on the County stuff).
I don’t see a filter for adjusting that HTML, but you could try formatting it via this: https://www.advancedcustomfields.com/resources/acf-render_field/
Basically you’d hijack the HTML it outputs with your own.
