"Reference not supported" with nested GROUP BY's on the same table and column

I had a very complex query (it was quite a complex view which used another pretty complex view).
It worked as expected in 10.1.*. I have tried it in 10.2.5 and 10.2.6 and throws the following error:
"Reference '[FIELD NAME]' not supported (forward reference in item list)".

I'm attaching the smallest example I have found which reproduces the issue (it's a useless construct for any other purpose).