create table test_tf
  (id      number,
   lvl     number,              -- level
   sifra   varchar2(10),
   naziv   varchar2(30),
   cb_nedo number(1)            -- checkbox
  );

insert into test_tf 
  select 1 id, 3 lvl, '1.1'     sifra, 'Heading 1 title' naziv, 0 cb_nedo from dual union
  select 2 id, 4 lvl, '1.1.1'   sifra, 'Heading 2 title' naziv, 0 cb_nedo from dual union
  select 3 id, 5 lvl, '1.1.1.1' sifra, 'Normal 1' naziv       , 0 cb_nedo from dual union
  select 4 id, 5 lvl, '1.1.1.2' sifra, 'Normal 2' naziv       , 1 cb_nedo from dual;

select
  apex_item.text(1, id, 2)     t_id,
  apex_item.text(2, lvl, 2)    t_lvl,
  apex_item.text(3, sifra, 4)  t_sifra,
  apex_item.text(4, naziv, 13) t_naziv,
  --
  apex_item.checkbox2(5, 
                      cb_nedo, 
                      case when lvl <> 5 then 'hidden="hidden"'
                           else case when cb_nedo = 1 then 'checked="checked"'
                                end
                      end
                     )     t_cb_nedo
from (select id,
             lvl,
             sifra,
             naziv,
             cb_nedo
      from test_tf
     )
order by id

case when lvl <> 5 then 'disabled="disabled"'