#!/usr/bin/perl
use strict;
use warnings;

use Data::Dumper;

my @sur = (
    { one => 'USA', two => 'GOD', three => 690557, four => 'hello how are u', },
    { one => 'USA', two => 'GOD', three => 690557, four => 'I am fine', },
    { one => 'UK',  two => 'GOD', three => 690558, four => 'I am Okay', },
);

my %h;

foreach my $row ( @sur ){
    my $three = $row->{ three };

    $h{ $three } .= exists $h{ $three }
        ? "####" . $row->{ four }
        : join "<-->", @{ $row }{ qw/one two four/ };
}

print Dumper \%h;