Hi there @Gopi_Nathan 
The thing is that our Google Reviews widget has a restriction on displaying only 100 last reviews. This way, you can apply your filters only among these 100 latest reviews.
Your 100 latest reviews have only 4 and 5-star rating, that’s why reviews with lower rating aren’t displayed in the widget.
Currently, unfortunately, we cannot extend this limit due to some technical reasons. But, we already have such a request in the Wishlist.
Feel free to vote for this feature to stay updated on any development - Display all reviews in the widget (remove 100 reviews limit)