title: How to extract the year from a URL path using REGEXP_EXTRACT in Google Data Studio?
body: <p>I'm building out a Google Data Studio dashboard and I need to create a calculated field for the year a post was published. The year is in the URI path, but I'm not sure how to extract it using <code>REGEXP_EXTRACT</code>.  I've tried a number of solutions proposed on here but none of them seem to work on Data Studio.</p>
  
  <p>In short, I have a URI like this: <code>/theme/2019/jan/blog-post-2019/</code></p>
  
  <p>How do I use the <code>REGEXP_EXTRACT</code> function to get the first 2019 after <code>theme/</code> and before <code>/jan</code>?</p>