How to make on change ajax work correctly?

Question

WordPress

Hello.

Wrote a post filter for Wordpress on ajax filter works correctly.

If, when changing select, I use and call ajax to get results, then the results are displayed only for one select field (the request array breaks), the question is: 1. How to make sure that on change takes into account all the data coming in POST? or when changing select do form submit? instead of calling ajax 2. How to make dependent select when changing to ajax? when one select is selected, only those select values ​​​​that the post with the first select has must remain in the others, etc.

$('select').on('change', function() {