# main nested hash
my %pages = (
	add_event_type => {
		show => {
			template => "add_evt",
			first_control => 'event_type_name',
			data => {
				event_type_name => { type => 'text', req => 1 },
				event_type_description => { type => 'text' },
			},
		},
	},
);

# elsewhere
my $page = "add_event_type";
my $action = "show";

# the code in question
my %page = %{ $pages{ $page }{ $action }};

# which allows, later
my $first_control = $page{ first_control };

# instead of 
my $first_control_again = $pages{ $page }{ $action }{ first_control };