I don't understand what you want to do, does this help? Does it inspire a new question?

#!/usr/bin/perl --
use strict; use warnings; use Data::Dump qw/ dd /;
my $record = {
    col1 => "value8",
    col2 => "value9",
    col3 => "value10|value11|value12",
    col4 => "value13|value14|value15",
};
dd( $record );
SomethingUnPipeModifyRecord( $record );
dd( $record );
dd( $record->{col4} );
dd( $record->{col4}[0] );

sub SomethingUnPipeModifyRecord {
    my( $rec ) = @_;
    for my $val( values %$rec ){
        my $newval = [ split /\|/, $val ];
        $val = $newval;
    }
    return $rec;
}
__END__
{
  col1 => "value8",
  col2 => "value9",
  col3 => "value10|value11|value12",
  col4 => "value13|value14|value15",
}
{
  col1 => ["value8"],
  col2 => ["value9"],
  col3 => ["value10", "value11", "value12"],
  col4 => ["value13", "value14", "value15"],
}
["value13", "value14", "value15"]
"value13"
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