Custom Filter On Post Listing

class-custom-post-filter.php

<?php
/**
 *
 * @wordpress-plugin
 * Plugin Name:       Custom Post Filter
 * Plugin URI:        http://uditrawat.com
 * Description:       Custom Post Filter For Posts
 * Version:           1.3
 * Author:            Udit Rawat
 * Author URI:        http://uditrawat.com
 * Text Domain:       fws
 */
class CustomPostFilter
{
    /**
     * Instance of this class.
     *
     * @since    1.0.0
     *
     * @var      object
     */
    protected static $instance = null;
    /**
     * Return an instance of this class.
     *
     * @since     1.0.0
     *
     * @return    object    A single instance of this class.
     */
    public static function get_instance()
    {
        // If the single instance hasn't been set, set it now.
        if (null == self::$instance) {
            self::$instance = new self;
        }
        return self::$instance;
    }
    /**
     * Class constructor
     *
     * @since     1.0.0
     */
    private function __construct()
    {
        // Add filter dropdown to admin view
        add_action('restrict_manage_posts', [$this, 'custom_filter']);

        // Alter query
        add_action('pre_get_posts', [$this, 'process_custom_filter']);

    }

    /**
     * @param null
     * @return null
     */
    function custom_filter()
    {

        global $typenow;
        $posttype = 'post';

        //only add filter to post type you want
        if ('post' == $typenow) {

            $current_filter = isset($_GET['author_id']) ? $_GET['author_id'] : '';

            $args = array(
                'orderby'       => 'name',
                'order'         => 'ASC',
                'show_fullname' => true,
                'echo'          => false,
            );

            $filter = get_users();

            $select = '<select name="author_id">';
            $select .= '<option value="">Select Author</option>';

            foreach ($filter as $value => $label) {


                $select .= sprintf(
                    '<option value="%s" %s >%s</option>',
                    $label->ID,
                    $value == $current_filter ? ' selected="selected"' : '',
                    $label->display_name
                );
            }
            $select .= "</select>";

            echo $select;
        }
    }

    /**
     * @param $query
     * @return null
     */
    function process_custom_filter($query){

        global $post_type, $pagenow;

        if ($pagenow == 'edit.php' && $post_type == 'post') {

            if (isset($_GET['author_id']) && $_GET['author_id'] != '') {

                $query->query_vars['author'] = $_GET['author_id'];

            }
        }

    }

}
if(class_exists('CustomPostFilter'))
    add_action( 'plugins_loaded', array( 'CustomPostFilter', 'get_instance' ) );

/*
You can also add meta query like below

$query->query_vars['meta_query'][] = [
                    'key' => 'cause_category',
                    'value' => '"' . $_GET['cause_category'] . '"',
                    'compare' => 'LIKE'
                ];
 */