you could build 'another' detail line, put the suppression formula for field2 in that, suppress the whole line and then check the formula for what it has.
would the supression for field 1 be,
if next(field2) = null?
or
next(field2) = null or next(field3) = null
or something else?
if it just checking if field 2 would be suppress, just add that to field1
HTH