add_action( \'post_submitbox_misc_actions\', \'show_current_filter\' );
add_action( \'post_submitbox_start\', \'show_current_filter\' );

function show_current_filter()
{
    $post = get_post();

    print \'<pre>\' .  $post->ID . \' : \' . current_filter() . \'</pre>\';
}

• https://codex.wordpress.org/Plugin_API/Action_Reference/post_submitbox_misc_actions
• https://developer.wordpress.org/reference/hooks/post_submitbox_start/