Is this what you wanted?
Note: this does handle the command->test thing you asked for as well. Will also prevent duplicates.

#!/usr/bin/perl                                                       
+                                               
use strict;
use Data::Dumper;

my @arr = qw(comp1-cmd1-test1 comp1-cmd1-test2 comp1-cmd2-test1 comp2-
+cmd1-test1 comp2-cmd1-test2 comp3-cmd1-test1);


my $ret_struct;
foreach my $element (@arr)
{
    my ($comp, $cmd, $test) = split(/\-/, $element);

    push(@{$ret_struct->{$comp}{$cmd}}, $test) 
         unless(grep(/$test/, @{$ret_struct->{$comp}{$cmd}}));

    push(@{$ret_struct->{$cmd}}, $test)
        unless(grep(/$test/, @{$ret_struct->{$cmd}}));

}

print Dumper($ret_struct);
[download]

Here is the output

$VAR1 = {
          'cmd2' => [
                      'test1'
                    ],
          'comp2' => {
                       'cmd1' => [
                                   'test1',
                                   'test2'
                                 ]
                     },
          'comp3' => {
                       'cmd1' => [
                                   'test1'
                                 ]
                     },
          'cmd1' => [
                      'test1',
                      'test2'
                    ],
          'comp1' => {
                       'cmd2' => [
                                   'test1'
                                 ],
                       'cmd1' => [
                                   'test1',
                                   'test2'
                                 ]
                     }
        };
[download]