title: Rewrite with haccess an old url with unknown subfolders to a an url with only the first "subfolder" from old url
body: <p>I'm trying to do a weird redirect in htaccess but i don't know how to do.</p>
  
  <p>I have old urls like:</p>
  
  <pre><code> 1. www.oldsite.com/known-old-folder/unknown-subfolder-1
   2. www.oldsite.com/known-old-folder/unknown-subfolder-2/unknown-second-subfolder-1
  </code></pre>
  
  <p>i have to redirect respectively to new urls like:</p>
  
  <pre><code> 1. www.newsite.com/known-new-folder/unknown-subfolder-1
   2. www.newsite.com/known-new-folder/unknown-subfolder-2
  </code></pre>
  
  <p>I don't want to consider "unknown-second-subfolder-1" if present.</p>
  
  <p>How can i do in htaccess?
  I don't know what to do in my <strong>RewriteRule</strong> to ignore the "unknown-second-subfolder-1" if present.</p>
  
  <p>Thanks a lot</p>