How to filter by category in smart filter?

Question

1C-Bitrix

There is an advanced search page. It contains the following components: Smart Filter and Section Elements.
Everything works, but you need a UI select box with a filter by Catalog category. How to implement?

Answer 1

Obviously: customize the smart filter component.
You can, of course, try and get by with customizing only the smart filter template. In this case, the core will not be affected.
This can be achieved by transferring the list of sections to the filter block and presenting it as a select (add the necessary JS scripts).

Answer 2

The marketplace has a combobox filter module that
can filter by sections and warehouses
Example
https://filter.kombox.ru/ajax/