You can count the order of occurrence of every attribute value using this expression in Field calculator (let's say, you want to count the order for the attribute "Id" and write it in the "order" attribute):
array_find(
array_agg($id, group_by:="Id"),
$id
) + 1
The result is:
After that you can select the duplicates with the expression:
"order" > 1
Hope this helps!