title: Querying firestore using multiple in clauses
body: <p>I'm working on a product listing page (similar to any e-commerce site) where users are expected to filter products based on multiple attributes and multiple values per attribute.</p>
  
  <p>Lets assume data model is as shown below,</p>
  
  <p><strong>Product</strong> <br />
      Category - Shirt <br />
      Size - Medium <br />
      Colour - Blue<br /></p>
  
  <p><strong>Dropdown filters on the search page would be</strong>,<br />
   1. Category: Shirts, T-Shirts, Trousers etc <br />
   2. Size: Medium, Large etc <br /></p>
  
  <p>I'm clueless as how to query firestore when user would like to search all Shirts &amp; T-Shirts of Small &amp; Medium sizes?</p>
  
  <p>Query like this isn't supported in firestore, </p>
  
  <pre><code>Firebase.firestore().collection("Products")
      .where("Category", "in", ["Shirt, "T-Shirts"])
      .where("Size", "in", ["Medium", "Large"])
  
  </code></pre>
  
  <p>On top of this, I need to paginate the response so filtering on the client side doesn't seem like an option.</p>
  
  <p>Please suggest if there is any option.</p>