my $ranges = [
               { I => "2", },
               { I => "3", J => "2", },
               { I => "4", J => "3", K => "2", }
             ];

foreach my $rvarHASH ( @{ $ranges } ) {
    my @rvarLIST = sort keys %$rvarHASH;
    my $depth = scalar @rvarList;
    my $array = BuildArray(\@rvarLIST, $depth);

    # do whatever with $array ...
}


sub BuildArray{
    my ($rvarLISTref, $depth) = @_;
    my $arrayref;
    $depth--;

    if ($depth > 0){
        # last dimension not reached, so do another recursion
        my $rtn = BuildArray($rvarLISTref, $depth);
        # get index, set ref to next dimension in array
        $ii = ...
        $arrayref->[$ii] = \$rtn;
    }else{
        # arrived at last dimension,
        # get index, set value into array
        $ii = ...
        $arrayref->[$ii] = $netlist;
    }

    return $arrayref;
}