可以使用函数来完成（可能还有其他方法）。只需要为每个令牌向outputcollector添加新的元组。
比如：

import static com.google.common.base.Preconditions.checkArgument;
import cascading.flow.FlowProcess;
import cascading.operation.BaseOperation;
import cascading.operation.Function;
import cascading.operation.FunctionCall;
import cascading.tuple.Fields;
import cascading.tuple.Tuple;

public class TestLateralView extends BaseOperation<Void> implements Function<Void> {
    private static final long serialVersionUID = 1L;

    public TestLateralView(Fields fields) {
        super(fields);
        checkArgument(fields.size() == 1);
    }

    @Override
    public void operate(@SuppressWarnings("rawtypes") FlowProcess flowProcess, FunctionCall<Void> functionCall) {
        Tuple tuple = functionCall.getArguments().getTuple();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < tuple.size(); i++) {
            sb.append(tuple.getString(i));
            sb.append(",");
        }

        String[] tokens = sb.toString().split(",");

        for (String token : tokens) {
            functionCall.getOutputCollector().add(new Tuple (token));
        }
    }
}

通过上述函数，我得到了预期的输出。
在程序集中，上述函数可以调用为：

pipe = new Each(pipe, CODES, new TestLateralView(CODE), Fields.ALL);