You can add a Ratings table to help with that. The structure would be somewhat like this.
I assume you may only want a user to rate a company once.
Create a “Rate & Comment” button on each company’s detail screen.
The form would contain a rating component and a text component (for comments). It will also collect the user’s rowID (from the Users table) and the company’s rowID (from the current table - Companies table).
In the Companies table, create a template joining the signed-in user’s rowID with each row’s company rowID.
In the Ratings table, create a template joining the user ID with the company ID.
Create a relation from the Companies table to the Ratings table using the 2 templates above.
If the relation is not empty, hide the “Rate & Comment” button.
You need two more columns in your Reviews table - one for UserID and one for CompanyID.
Both of these should be populated from your Review Form. The CompanyID will be available as a Screen Value, and the UserID can be taken from the User Profile of the user submitting the form.
Once you have those values being recorded, you can use them to build the relation that @ThinhDinh described: