%hash = (
	foo => {
		this => '...',
		that => '...',
		here => '...',
		there => '...'
		},
	bar => {
		this => '...',
		that => '...',
		here => '...',
		there => '...'
		}
);

##</code><code>##

for (sort { $hash{$a}->{this} <=> $hash{$b}->{this} } keys %hash)