use strict;
my $text='(one dfd(two(three)four()(five)df())df)';

print $& if $text=~m#(\([^()]*(\([^()]*\))+[^)]*\))+#;

##</code><code>##

(two(three)four()

##</code><code>##

(one dfd(two(three)four()(five)df())df)