I'd do it this way. Encapsulate and abstractulate as appropriate:

my $num = shift;
my $bits = 6;
my $mask = (1 << $bits) - 1;

my @out = map {
    ($num & $mask << $_ * $bits)
    >> $_ * $bits
} 0..$bits-1;
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update: oops, the map 0 .. $bits-1 is just a fortunate accident of 5 == 6-1. The following is better:

my $num    = shift;
my $groups = 5;
my $bits   = 6;
my $mask   = (1 << $bits) - 1;

my @out = map {
    ($num & $mask << $_ * $bits)
    >> $_ * $bits
} 0..$groups-1;
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2nd update: oh, and you want to go back the other way. That's even easier:

my @in  = (30, 14, 27, 2, 17);
my $width  = 6;

my $offset = 0;
my $out = 0;
$out |= ($_ << ($offset++ * $width)) for @in;
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