Hmm... it looks to me that you should read up on database design and SQL. You can solve it like this in Perl, but I wouldn't. Oh and I would use DBD::ODBC instead, so your code would be a bit more portable.

I'd make several tables for business_unit, group, subgroup and application, referering to each other where appropriate. and a cross table between subgroup and application.

Then do something like:

my $result = $dbh->selectall_arrayref(
   "SELECT application.name FROM application, group, subgroup, app_sub
+group WHERE
   application.id =  app_subgroup.application AND 
   app_subgroup.subgroup = subgroup.id AND
   subgroup.group = group.id AND group.name='Procurement'"
);
foreach (@$result) {
   print @$_;
}
[download]

With the current model it would look like:

my $result = $dbh->selectall_arrayref(
   "SELECT DISTINCT(application) FROM table_name WHERE
   group_name='Procurement'"
);
foreach (@$result) {
   print @$_;
}
[download]

Which is simpler, but will get you in trouble later on when your table starts getting bigger and bigger and people start spelling Internet Explorer as "Internt Explorer".