use strict;
use warnings;

my %HoH = (
    SUB1 => {
        Test1 => {
            value1   => "2300",
            value2   => "0.01",
        },
        Test2 => {
            value1   => "5000",
            value2     => "0.34",
        },
    },
    SUB2 => {
        Test1 => {
            value1   => "2800",
            value2   => "0.05",
        },
    },
);

my %hoa;
for my $I (sort keys %HoH){
  for my $J (sort keys %{ $HoH{$I}  })  {
    for my $K (sort keys %{  $HoH{$I}{$J} } ){
     push @{$hoa{$J}}, [$I,$K, $HoH{$I}{$J}{$K}];
    } 
  }
}


for my $k (sort keys %hoa){
  my $entry=$hoa{$k};
  print "For $k\n";
  for my $item(sort {$a->[1] cmp $b->[1] } @$entry){
    print "   $item->[0] has $item->[1]=$item->[2]\n" 
  }
}
__OUTPUT__
For Test1
   SUB1 has value1=2300
   SUB2 has value1=2800
   SUB1 has value2=0.01
   SUB2 has value2=0.05
For Test2
   SUB1 has value1=5000
   SUB1 has value2=0.34