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

##</code><code>##

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