Retrieve Child inside getKey

Question

I have a Recycler Adapter with a populateViewHolder that when I click takes the Child key in firebase, in the image box below takes KeGVDMcSt0v5HICwuUm

  @Override
  protected void populateViewHolder(ChatViewHolder viewHolder, Chat model, int position) {
  final String post_key = getRef(position).getKey();

so are the Child

                                                     I send the key to the other activity with singleBlogIntent.putExtra"blog_id", post_key);

and recover with mPost_key = getIntent().getExtras().getString("blog_id");

only that I need to take the value uid hC7y1BKtAWTFR&zoXVkr3oYjLTS2 inside that Child.

I can’t explain in technical terms and even less if the title matches the question , I thank you from now on.

Updating

I intend to recover so, compare the uid that in the case would have to be the "blog_id" and catch the user since id on Child Users

   final String currentUserId = getIntent().getExtras().getString("blog_id");
   mDatabaseCurrentUser = FirebaseDatabase.getInstance().getReference().child("Users");
   mQueryCurrentUser = mDatabaseCurrentUser.orderByChild("uid").equalTo(currentUserId)