ora 01427 - Oracle Single row subquery returns multiple rows while using nested subquery -

i'm trying run query below throws 'single row subquery returns multiple rows' error. works = in place of <> though(returns more 50 rows final output). not able figure out whats going wrong when use <>.tried not in, doesn't work. please help.

select a,        b,        c,        d,        e      (select distinct column1 a,                     column2 b,                     column3 c,                     column4 d,                     column5 e      t1      t1.column1 'domain.%') c||d||e <> 'yyy' 

this hunch think missing inline view alias in query here shown below

from     (select distinct column1 a,                     column2 b,                     column3 c,                     column4 d,                     column5 e      t1      t1.column1 'domain.%') xxx <-- 1 

also, try using concat() function instead like

where concat(concat(c,d),e) <> 'yyy'