Join on multiple columns with OR
I don't think there is a way to get this query to perform well, but the code will be easier to read if you use the IN predicate:

select * 
from tbl1 t1 
join tbl2 t2 
    on t1.col1 in (t2.col1, t2.col2, ...) 
    or ...
    or t1.col5 in (t2.col1, ... )