To get all the FEATURES:

my @features = $seq->all_SeqFeatures();
To get all the features filtering on only those which have the primary tag (IE. feature type) exon.
my @genes = grep { $_->primary_tag eq 'exon'}
$seq->all_SeqFeatures();
To get all the features filtering on this which have the /NOTE tag and WITHIN the note field contain the requested string $noteval.
my @f_with_note = grep { my @a = $_->has_tag('note') ? $_->each_tag_value('note') : ();
grep { /$noteval/ } @a; } $seq->all_SeqFeatures();

To get all the features:

my @features = $seq->all_SeqFeatures();
To get all the features filtering on only those which have the primary tag (ie. feature type) exon.
my @genes = grep { $_->primary_tag eq 'exon'}
$seq->all_SeqFeatures();
To get all the features filtering on this which have the /note tag and within the note field contain the requested string $noteval.
my @f_with_note = grep { my @a = $_->has_tag('note') ? $_->each_tag_value('note') : ();
grep { /$noteval/ } @a; } $seq->all_SeqFeatures();