Nested 'group's about latitude HOT 3 CLOSED

$select->where(field('something')->eq(1));

$is90Days = group(
    field('po.po_duration_magnitude')->eq('90')->and(
        field('po.po_duration_unit')->eq('Days')
    )
);
$is12Weeks = group(
    field('po.po_duration_magnitude')->eq('12')->and(
        field('po.po_duration_unit')->eq('Weeks')
    )
);

$select->addWhere(group($is90Days->or($is12Weeks)));