Nginx forwarding based on URL parameters

server {
  listen 83;
  server_name localhost;
  index index.html index.htm;

  root D:/workspace-xxxx/xxx_Web;

  error_page 500 502 503 504 / 50x.html;
  location = /50x.html {
      root html;
    }
  location ^~ /xxx/ {
    proxy_pass http://192.168.60.36:8090/xxxx/;
    proxy_redirect default;
    proxy_set_header Host $host;
    proxy_set_header X - Real - IP $remote_addr;
    proxy_set_header X - Forwarded - Host $host;
    proxy_set_header X - Forwarded - Server $host;
    proxy_set_header X - Forwarded - For $proxy_add_x_forwarded_for;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
  }

# Here is the path after bimg4 in the request address and assigned to the forwarding address location ^ ~ / bimg4 / {
    if ($request_uri~ / bimg4 / (. * )) {
      set $bucketid $1;
    }
    proxy_pass http: //$bucketid;
  }
}