这可能不是您的全部解决方案，因为您没有发布任何代码，因此我无法将我所知道的内容与任何内容结合起来，但是，下面的代码片段将把一个图像作为附件上传到自定义目录中，该目录是在执行时创建的。我已经对关键行进行了评论。。。

function upload_to_new_dir() {
    global $post;

    //This gets the main uploads directory
    $upload_dir     = wp_upload_dir();
    
    //This sets a path to a new directory which we\'ll make, ie. \'/uploads/the-post-slug/\'
    $make_new_dir   = $upload_dir[\'basedir\'] . $post->post_name;
    
    //Now we check if the directory already exists, if not, we make it
    if( !file_exists ( $make_new_dir ) ) :
        wp_mkdir_p( $make_new_dir );
    endif;

    //This gets the image file from an AJAX form for me, you\'ll have to find your own method
    $img_file           = $_FILES[\'img_file\'];

    //Now set WHERE the image is going to be uploaded
    $upload_file        = $make_new_dir . \'/\' . basename( $img_file[\'name\'] );

    //Move the uploaded file to the location specified
    move_uploaded_file( $img_file[\'tmp_name\'] , $upload_file );

    //Get the name of the image file so we can record it somewhere
    $img_name           = basename( $upload_file );

    //Everything below here is for attaching an image as an $attachement
    //And setting it as the post thumbnail
    //I don\'t know if this is what you need or if you need another method
    $wp_filetype        = wp_check_filetype( basename( $img_name ), null );
    $attachment = array(
            \'post_mime_type\'    => $wp_filetype[\'type\'],
            \'post_title\'        => $img_name,
            \'post_content\'      => \'\',
            \'post_status\'       => \'inherit\',
            \'menu_order\'        => $_i + 1000,
    );
    $img_id         = wp_insert_attachment( $attachment, $upload_file );
    if( !update_post_meta ( $post->ID, \'_thumbnail_id\', $img_id ) ) {
        add_post_meta( $post->ID, \'_thumbnail_id\', $img_id, true );
    };
    set_post_thumbnail( $post->ID, $img_id );
}
//YOU NEED TO DETERMINE WHAT ACTION TO USE TO EXECUTE THIS

我的建议是不要干扰媒体库的默认操作，而是构建自己的函数，从管理端javascript使用AJAX执行。

如果你这样做，你想要的行动是

add_action(\'wp_ajax_nameofajaxaction\', \'upload_to_new_dir\');

您还需要创建一个nonce，并在上述函数的开头使用以下各项检查nonce：

check_ajax_referer();

一些轻松的阅读：https://developer.wordpress.org/reference/functions/check_ajax_referer/https://codex.wordpress.org/AJAX_in_Plugins