Generate a list from columns that do not contain a zero for each row

The question is which of the pdates for a module do you want to use for ordering purposes?

If you are happy to use the largest, you could use:

select module from logging order by max(pdate); 

--- EDIT

I think I get it now - you probably want something like this:

select module
from( select module, 
             sum(module_step) over (order by pdate rows unbounded preceding) 
                 as batch_number, 
             pdate
      from( select module, 
                   case lag(module) over (order by pdate) when module then 0 
                        else 1 end as module_step, 
                   pdate from logging) )
group by module, batch_number
order by batch_number;

For something more complex you might need a regular expression, but in this case, the following should suffice.

SELECT DISTINCT SUBSTR(URL,INSTR(URL,'/',-1)+1) 
FROM TABLE1 
WHERE URL IS NOT NULL 
ORDER BY 1;

Sample data.

create table table1 (URL Varchar2(1000));
insert into table1 values ('Test1/Admin/Page7.asp');
insert into table1 values ('Test1/One/Page3.asp');
insert into table1 values ('Test1/Another/Page2.asp');
insert into table1 values ('Testing1/Admin2/Page12.asp');
insert into table1 values ('Page7.asp');
commit;