`WITH` statement inside subqueries

### Company or project name

_No response_

### Question

Hi! I noticed a strange behavior of the `WITH` statement when using subqueries.
For some reason this doesn't work:

```sql
with
A = 2 as selector
select sum(value) from (
select * from test_table where selector

union all

select * from test_table
)
```

While this DOES:
```diff
+select sum(value) from (
with
A = 2 as selector
-select sum(value) from (
select * from test_table where selector

union all

select * from test_table
)
```

I really want to write it the first way because I want to access some stuff in the global scope and it is less convenient to nest the `WITH` statements in my opinion.

So is it a behavior I did not get? If so, is that explained somewhere in the docs?

Thanks in advance 😊