This gist is used in the tutorial https://www.vijayan.in/how-to-create-custom-table-list-in-wordpress-admin-page

extra_tablenav.php

<?php
...
	/**
	 * Overriden method to add dropdown filters column type.
	 *
	 * @param string $which Position of the navigation, either top or bottom.
	 *
	 * @return void
	 */
	protected function extra_tablenav( $which ) {

		if ( 'top' === $which ) {
			$drafts_dropdown_arg = array(
				'options'   => array( '' => 'All' ) + $this->allowed_post_types_readable(),
				'container' => array(
					'class' => 'alignleft actions',
				),
				'label'     => array(
					'class'      => 'screen-reader-text',
					'inner_text' => __( 'Filter by Post Type', 'admin-table-tut' ),
				),
				'select'    => array(
					'name'     => 'type',
					'id'       => 'filter-by-type',
					'selected' => filter_input( INPUT_GET, 'type', FILTER_SANITIZE_STRING ),
				),
			);

			$this->html_dropdown( $drafts_dropdown_arg );

			submit_button( __( 'Filter', 'admin-table-tut' ), 'secondary', 'action', false );
		}
	}
...