oracle regexp on input string based on multiple lines

 https://stackoverflow.com/questions/38738732/oracle-regexp-substr-find-and-extract-all-occurances-in-a-column

Try this query to break ABC123CDE456FGHI789 squence

with mine as (select 'ABC123CDE456FGH789' hello from dual) 

select regexp_substr(hello, '[A-Za-z]{3}(\d){3}', 1, level) STR from mine

connect by regexp_substr(hello, '[A-Za-z]{3}(\d){3}', 1, level) is not null

Output:

ABC123

CDE456

GHI789