my %hash = ();
my @array = qw(familie
familie/papa
familie/papa/auto
familie/papa/computer
familie/mama
freunde
freunde/michael
freunde/monique
hobbies/sport
hobbies/sport/fussball);

for my $elem(@array){
  my ($root) = split(/\//,$elem);
  next if(exists($hash{$root}));
  $hash{$root} = $elem;
}

my @unique = values(%hash);