title: MongoDb: find(), property of document matches one value of given array
body: <p>So I'm making a search bar in my app and I'm using mongodb to fetch the results.
  The situation is as following:</p>
  
  <p>When the _group property (which is an ObjectId) of the post document is equal to one of the values in the exampleArray I want this post to be included in my end result. How would I do this? </p>
  
  <pre><code> const exampleArray = ['ObjectId1', 'ObjectId1', 'ObjectId1'];
  
      const posts = await Post.find({_group: exampleArray })
  </code></pre>