About treelistview ...

You asked this yesterday. Why delete and repost the same question?

Have you thought about why no one answered? A lot of the time it is due to the question that is asked. You only specify the tag C#, you do not post any code that you have tried. Also, we do not know what type of app you are trying to do this in. Is it Winform, WPF, Asp.net, MVC, Blazor, Xamarin, MAUI, etc... When asking questions, please articulate with more specific information (including the application type); code tried; the full error message encountered including which line the error occurred on (with the code); etc. Information that we need to better understand your issue as we cannot see your screen with code in here.

Also, we are not a free coding service. We are more than happy to assist you with your code.

Now, to help you with researching a solution, I did the following Google Search based on the information in your question: gridview as treelistview c#[^]

Here are a couple of more refined searches based on the type of app:
1. winform gridview treeview c#[^]
2. wpf gridview treeview c#
3. asp.net gridview treeview c#[^]

As you can see, each search returns slightly different results.

If you still need help, Please do not delete this question, instead, update it (by using the improve question link underneath the question / to the right of your name) with more information, and the question will rise to the top of the list.