A slightly different approach:

>perl -wMstrict -le
"my %fruits = (
   pear => {
     apple => {
       peach => 'pear_apple_peachy',
       },
     damson => {
       orange => 'pear_damson_orangish',
       },
     },
   );
 ;;
 my ($ch1, $ch2, $ch3) = qw(pear damson orange);
 ;;
 print qq{a $ch1-$ch2-$ch3 is $fruits{$ch1}{$ch2}{$ch3}}
"
a pear-damson-orange is pear_damson_orangish
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See perldsc.