Compairing two values javascript node.js mongodb

First of all i have these mongoose schemas user schema

var UserSchema = new mongoose.Schema({
username: String,
email: String,
password: String,
types: [
  {
     type: String,
     ref: "types"
  }
 ], 
follow: [
  {
     type: mongoose.Schema.Types.ObjectId,
     ref: "follow"
  }
]
});

and the blog schema

  var blogSchema = new mongoose.Schema({
  title: String,
  image: String,
  body: String,
  category: String,
  author: {
  id: {
     type: mongoose.Schema.Types.ObjectId,
     ref: "User"
  },
  username: String
  }, likes: [
  {
     type: mongoose.Schema.Types.ObjectId,
     ref: "likes"
  }
 ],
 comments: [
  {
     type: mongoose.Schema.Types.ObjectId,
     ref: "Comment"
  }
],
created: {type: Date, default: Date.now}
});

Now i have made it so user.follow and blog.author.id so that for some users those have the same id but the thing is that i want to be able to show in a ejs file all the blogs that have the same id. I have tried this

<% var specificBlogss = 
currentUser.follow.valueOf()currentUser.follow.indexOf == blog.author.id) %>
 <% specificBlogss.forEach(function(blog){ %>
//things about the blogs
<%} %>

via fanffis theologiths