nginx_reverse_proxy_with_url_rewrite.conf

server {
        listen 80;
        listen [::]:80;
        server_name cdn-images.example.com;
        server_tokens off;
        location / {
                rewrite ^/(.*)/subfolder/(.*)$ /images/$1/anothersubfolder/anothersubfolder/$2;
                proxy_pass https://my-bucketname.ams3.digitaloceanspaces.com/;
                proxy_hide_header      Strict-Transport-Security;
        }
}