Add Custom Columns to WordPress Post List Page

custom_wordpress_columns.php

<?php

add_filter( 'manage_posts_columns', 'your_custom_cols' ); //Filter out Post Columns with 2 custom columns

function your_custom_cols($defaults) {
    $defaults['language'] = __('Language'); //Language and Films is name of column
    $defaults['film'] = __('Films');
    return $defaults;
}

add_action('manage_posts_custom_column', 'custom_cols_data', 10, 2); //Just need a single function to add multiple columns

function custom_cols_data($column_name, $post_id) {
    global $wpdb;
    if( $column_name == 'language' ) { 
			$tags = get_the_terms($post->ID, 'lang'); //lang is the first custom taxonomy slug
			if ( !empty( $tags ) ) {
				$out = array();
				foreach ( $tags as $c )
					$out[] = &quot;<a href='edit.php?lang=$c->slug'> &quot; . esc_html(sanitize_term_field('name', $c->name, $c->term_id, 'lang', 'display')) . &quot;</a>&quot;;
				echo join( ', ', $out );
			} else {
				_e('No Languages.');  //No Taxonomy term defined
			}
		} else if( $column_name == 'film' ) {   //Adding 2nd column
			$tags = get_the_terms($post->ID, 'film'); //film is the next taxonomy slug for column Films
			if ( !empty( $tags ) ) {
				$out = array();
				foreach ( $tags as $c )
					$out[] = &quot;<a href='edit.php?film=$c->slug'> &quot; . esc_html(sanitize_term_field('name', $c->name, $c->term_id, 'film', 'display')) . &quot;</a>&quot;;
				echo join( ', ', $out );
			} else {
				_e('No Related Films.'); //no Films found
			}
		} else {
            echo '<i>'.__('None').'</i>'; //Only 2 columns, blank now.
        }
    }
?>