with ORD as (
select SESSION_ID, 
--PROCESS_ID
group_concat(replace(PROCESS_ID,"STEP",""),"") as ord
from PROCESS_LOG 
group by 1),
tmp as(
select 
count(1) as CNT,
case
when ord = "12345" then "5"
when ord = "1234" then "4"
when ord = "123" then "3"
when ord = "12" then "2"
when ord = "1" then "1"
else "0"
end as steps
from ORD
group by steps
order by steps
)
select "STEP"||steps as PROCESS, CNT from tmp where steps !="0"