G'day Special_K,

Your prosaic description of the data structure is not entirely clear. I've made the assumption that "Each corner will have the same number of suffixes for a given meas name." means you have a structure like this:

{
  meas_1 => {
    suffix_1 => { C1 => { value => 10.2 }, C2 => { value => 110.2 } },
    suffix_2 => { C1 => { value => 4.7 },  C2 => { value => 204.7 } },
    suffix_3 => { C1 => { value => 5.2 },  C2 => { value => 305.2 } },
    suffix_4 => { C1 => { value => 11.8 }, C2 => { value => 411.8 } },
    suffix_5 => { C1 => { value => 0.7 },  C2 => { value => 500.7 } },
  },
}
[download]

If that assumption is incorrect, please provide a clearer description of what you do have (showing example data instead of a narrative).

Based on my assumption, this code does what you want:

#!/usr/bin/env perl

use strict;
use warnings;

my (%data, %ordered_hash);

$data{meas_1}{suffix_1}{C1}{value} = 10.2; 
$data{meas_1}{suffix_2}{C1}{value} = 4.7;
$data{meas_1}{suffix_3}{C1}{value} = 5.2;
$data{meas_1}{suffix_4}{C1}{value} = 11.8; 
$data{meas_1}{suffix_5}{C1}{value} = 0.7;
$data{meas_1}{suffix_1}{C2}{value} = 110.2;
$data{meas_1}{suffix_2}{C2}{value} = 204.7;
$data{meas_1}{suffix_3}{C2}{value} = 305.2;
$data{meas_1}{suffix_4}{C2}{value} = 411.8;
$data{meas_1}{suffix_5}{C2}{value} = 500.7;

for my $meas (keys %data) {
    my @suffixes = keys %{$data{$meas}};
    for my $corner (keys %{$data{$meas}{$suffixes[0]}}) {
        push @{$ordered_hash{$meas}{$corner}},
            map { $_->[0] }
            sort { $b->[1] <=> $a->[1] }
            map { [ $_ => $data{$meas}{$_}{$corner}{value} ] } @suffix
+es;
    }
}

use Data::Dump;
dd \%ordered_hash;
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Output:

{
  meas_1 => {
    C1 => ["suffix_4", "suffix_1", "suffix_3", "suffix_2", "suffix_5"]
+,
    C2 => ["suffix_5", "suffix_4", "suffix_3", "suffix_2", "suffix_1"]
+,
  },
}
[download]