How to find identical rows with the same Property values and filter those rows?

I am not sure if it´s possible to use TGVs to display only duplicates. When you just want to do this for validation from admin side it´s maybe easier to achieve with an SQL View. 

You can use filter for Tree Grid Views to filter your result for 'AAA'. But in this case you need to know the value you are looking for. 

See: https://community.aras.com/b/english/posts/tech-tip-filter-a-tree-grid-view-with-parameters