Source

File: wp-admin/includes/class-wp-posts-list-table.php

protected function categories_dropdown( $post_type ) {
		global $cat;

		/**
		 * Filters whether to remove the 'Categories' drop-down from the post list table.
		 *
		 * @since 4.6.0
		 *
		 * @param bool   $disable   Whether to disable the categories drop-down. Default false.
		 * @param string $post_type Post type slug.
		 */
		if ( false !== apply_filters( 'disable_categories_dropdown', false, $post_type ) ) {
			return;
		}

		if ( is_object_in_taxonomy( $post_type, 'category' ) ) {
			$dropdown_options = array(
				'show_option_all' => get_taxonomy( 'category' )->labels->all_items,
				'hide_empty'      => 0,
				'hierarchical'    => 1,
				'show_count'      => 0,
				'orderby'         => 'name',
				'selected'        => $cat,
			);

			echo '<label class="screen-reader-text" for="cat">' . __( 'Filter by category' ) . '</label>';
			wp_dropdown_categories( $dropdown_options );
		}
	}