Basically you have to hide every node except the root node, and then call autosetmode().
my $tree = '/home';
my ($File, $Temp, @Dir_List);
foreach $File (@Dir_List)
$Temp = (split('/', $File))[-1];
$Temp = $File unless defined $Temp;
$Tree->add($File, -text => "$Temp");
This starts out with a (+) beside the root node, then when you expand the root node shows the next level in the tree each with a (+), then when you expand each node, it will show its children with a (+), etc.
What time is it? It's Camel Time!