use UI::Dialog;
my $d = new UI::Dialog( backtitle => 'Demo', title => 'Default', );

my @selection1 = $d->checklist(
    text => 'Select one:',
    list => [
        'tag1', [ 'item1', 0 ], 'tag2', [ 'item2', 1 ], 'tag3', [ 'item3', 1 ]
    ]
);
foreach my $sel (@selection1) {
    printf( "%s\n", $sel );
}

$ perl ~/ex.pl 
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
tag2$
tag3