title: Cloud functions onWrite for dynamically generated refs
body: <p>Here is how data is structured in my realtime database:</p>
  
  <p><a href="https://i.stack.imgur.com/swuYb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/swuYb.png" alt="enter image description here"></a></p>
  
  <p>I have a realtime database setup as shown in the image above. I would like to take all the children in products onWrite and add them to an allProducts ref which will be under uid. My document structure is like stocks > uid > category> products. Followed the documentation buts its not showing for ambiguous refs </p>