Group by alias (Oracle)

Question

How to \'group by\' a query using an alias, for example:

select count(*), (select * from....) as alias_column 
from table 
group by alias_column

Answer 1

select count(*), (select * from....) as alias_column 
from table 
group by (select * from....)

In Oracle you cannot use an alias in a group by clause.