See Tk::BrowseEntry, you don't need to use variable option, the callback gets the option text

#!/usr/bin/perl --
use strict;
use warnings;
use Tk;
use Tk::BrowseEntry;

Main( @ARGV );
exit( 0 );

sub Main {
    GoTk();
    GoTk();
}

sub GoTk {
    my $mw = tkinit;
    my $b = $mw->BrowseEntry(
        -browsecmd => \&tura,
    )->pack;
    $b->insert("end", "Tapioca");
    $b->insert("end", "Figgy duff");
    $b->insert("end", "Haggis");
    $mw->MainLoop;
}

sub tura {
    print "@_\n";
}
__END__
$ perl tk-scope-BrowseEntry-tura.pl
Tk::BrowseEntry=HASH(0xb9298c) Haggis
Tk::BrowseEntry=HASH(0xb9298c) Tapioca
Tk::BrowseEntry=HASH(0xb9298c) Figgy duff
Tk::BrowseEntry=HASH(0xfb3844) Figgy duff
[download]