Update: Or more compactly. Use as below.

sub x {
    my $aref = shift;
    my( $name, @kids ) = @_;
    push @{ $aref }, { name => $name }
        unless @$aref and $aref->[ -1 ]{ name } eq $name;
    x( $aref->[ -1 ]{ children } ||= [], @kids ) if @kids;
}
[download]

#! perl -slw
use strict;
use Data::Dumper;

sub x {
    my $aref = shift;
    my( $name, @kids ) = @_;
    unless( @$aref and $aref->[ -1 ]{ name } eq $name ) {
        push @{ $aref }, { name => $name };
    }
    if( @kids ) {
        if( not exists $aref->[ -1 ]{ children } ) {
            $aref->[ -1 ]{ children } = [];
        }
        x( $aref->[ -1 ]{ children }, @kids );
    }
}

my @data;
chomp() and x( \@data, split ' / ', $_ ) while <DATA>;

print Dumper \@data;

__DATA__
one
foo / bar
foo / baz
foo / qux / two
foo / qux / three
foo / qux / four
five
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Produces

c:\test>junk9 | more
$VAR1 = [
          {
            'name' => 'one'
          },
          {
            'name' => 'foo',
            'children' => [
                            {
                              'name' => 'bar'
                            },
                            {
                              'name' => 'baz'
                            },
                            {
                              'name' => 'qux',
                              'children' => [
                                              {
                                                'name' => 'two'
                                              },
                                              {
                                                'name' => 'three'
                                              },
                                              {
                                                'name' => 'four'
                                              }
                                            ]
                            }
                          ]
          },
          {
            'name' => 'five'
          }
        ];
[download]