It's not Grid with row details. You have completely gone on wrong direction here.
If you wanted to have grid with row detail, it's master-detail type grid:
MSDN: GridView Examples for ASP.NET 2.0: Displaying Master/Detail Data in a GridView[
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What you shared is a tree on left hand side and a tab corresponding to it on right hand side.
Have a look at this article to start on:
ClientCallback custom control for web applications[
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You need to define a tree and on node selection show a tab control on right side based on the tree selection.
Above example is using Callback. You can also use AJAX to implement the same. Pick the one that suits you and go ahead. Try out. If you face issues, please post specific issue.