Select 'loans' as product, inn s
from potential
where type in ('SHOW', 'SHOW_FRONT')
  and (1 = l_loans or 1 = l_acq or 1 = l_zp)
  and calc_id = l_calc_id
group by inn having (1 = l_loans and sum(abs(cltv_loan))=0) or (1 = l_acq and sum(abs(cltv_acq))=0) or (1 = l_zp and sum(abs(cltv_salary))=0)

Select 'loans' as product, inn s
from potential 
     cross join (select level rn from dual connect by level <= decode(l_loans, 1, 1, 0) + decode(l_acq, 1, 1, 0) + decode(l_zp, 1, 1, 0)) rpt
where type in ('SHOW', 'SHOW_FRONT')
  and (1 = l_loans or 1 = l_acq or 1 = l_zp)
  and calc_id = l_calc_id
group by rpt.rn, l_loans, l_acq, l_zp, inn
  having (1 = l_loans and sum(abs(cltv_loan))=0 and rpt.rn = 1 )
      or (1 = l_acq and sum(abs(cltv_acq))=0 and rpt.rn = decode(l_loans, 1, 1, 0) + 1)
      or (1 = l_zp and sum(abs(cltv_salary))=0 and rpt.rn = decode(l_loans, 1, 1, 0) + decode(l_acq, 1, 1, 0) + 1)