Filter by author (drop-down list of authors) in the admin posts table
In this note, we'll look at how to add a new filter by author to the posts table in the admin panel.
The problem is this: There is a site with multiple authors, but no way to filter posts by a specific author. The code below adds a dropdown list filter of posts authors to the posts table in the WordPress admin panel (next to the date and category dropdown lists).
if( is_admin() ){
add_action( 'restrict_manage_posts', 'wp_posts_list__author_dropdown' );
function wp_posts_list__author_dropdown( $post_type ){
if( ! in_array( $post_type, ['page','post'] ) ){
return;
}
wp_dropdown_users( [
'show_option_all' => 'Все авторы',
'selected' => get_query_var( 'author', 0 ),
'name' => 'author',
'who' => 'authors',
// 'role__in' => ['author','editor','administrator'],
] );
}
}
We get it:

The code uses a function and a hook:
I recommend to get familiar with their work to better understand what the code does.
Read also: how to add your filters to different tables in the admin: posts, categories, users, comments.