my %rehash;
for my $SUBNAME (sort keys %HoH){
  for my $testname (sort keys %{ $HoH{$SUBNAME}  })  {
     my $val =  $HoH{$SUBNAME}{$testname}{value1};
     if (exists  $rehash{$testname}{$SUBNAME}{value1}
         and     $rehash{$testname}{$SUBNAME}{value1} > $val){
       # Do not update - greater value exists
     }else{
       $rehash{$testname}{$SUBNAME} = $HoH{$SUBNAME}{$testname};
     }
  }
}


for my $testname (sort keys %rehash){
   print "For $testname:\n";
   for my $SUBNAME(sort keys %{ $rehash{$testname} }){
     print "   $SUBNAME has " 
       , map( {" $_=$rehash{$testname}{$SUBNAME}{$_};"} sort keys %{$rehash{$testname}{$SUBNAME}}),
       ,"\n";
  }
}
__OUTPUT__
For Test1:
   SUB1 has  value1=2300; value2=0.01;
   SUB2 has  value1=2800; value2=0.05;
   SUB3 has  value1=2700; value2=0.25;
For Test2:
   SUB1 has  value1=5000; value2=0.34;
   SUB2 has  value1=5500; value2=0.34;
   SUB3 has  value1=5800; value2=0.45;
For Test3:
   SUB1 has  value1=3000; value2=0.10;
For Test4:
   SUB1 has  value1=7000; value2=0.33;