What does your feature entail? What is it for? How will it affect existing workflows or user experience?
The way it works now is tabs get together in subtrees if they are new websites that have had access from the "main" tab, this sometimes lead to subtrees of websites that don't go along. It usually happens when researching for a paper.
What are the exact ways that you see a user using your proposed feature? Please go into as much detail as possible, and provide examples of how other browsers/apps implement this feature, if applicable. If your feature suggestion adds on to an existing feature, how would it work into it to extend its usefulness?
By giving the option to group them by website, it will lead to a more cohesive workspace as it's easier for the user to understand where each tab is. This could be a feature, the user could choose between how it is now and my suggestion.