Thank you for posting this question! Please read the article below in order to learn how to filter the reviews by a specific number of stars, for example, show the reviews only with 4 and 5 stars.
In order to enable the setting for showcasing the reviews with 4 stars and above you will need to:
1. Navigate to the widget where you would like to make the changes and click on the 'Filters' tab:
2. In the dropdown on the 'Minimum rating' setting, select 4:
That's it! Now your widget will be shown only the reviews that have 4 and 5 stars! You can make different combinations as well.