use Text::Balanced;

my $str = "  ['listliteral',['ListLiteral',['../classSPL_1_1Operator_1_1Instance_1_1ExpressionTree_1_1ListLiteral.html',1,'SPL::Operator::Instance::ExpressionTree']]]";


@matches = Text::Balanced::extract_bracketed( $str, '[]' );

foreach (@matches) {
    print "$_\n";
}