#!/usr/bin/perl
use Data::Dumper;
use XML::Simple;

use strict;
use warnings;

my $data = do {local $/; <DATA>};
my $xml = XMLin($data);
print Dumper($xml);

__DATA__
<Parameters>
<ParameterGroup ID="Group1">
<Parameter key="Key1">Some Value</Parameter> 
<Parameter key="Key2">Some Value</Parameter> 
<Parameter key="Key3">Some Value</Parameter> 
</ParameterGroup>
<ParameterGroup ID="Group2">
<Parameter key="Key1">Some Value</Parameter> 
<Parameter key="Key2">Some Value</Parameter> 
<Parameter key="Key3">Some Value</Parameter> 
</ParameterGroup>
</Parameters>