要将多个条件添加到DynamoDB的FilterExpression中，您可以使用aws-sdk-go库的ConditionBuilder类型来构建复杂的筛选条件。以下是一个示例代码，展示了如何使用ConditionBuilder来构建FilterExpression：

package main

import (
	"fmt"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/dynamodb"
	"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
)

func main() {
	// 创建DynamoDB客户端
	sess := session.Must(session.NewSessionWithOptions(session.Options{
		SharedConfigState: session.SharedConfigEnable,
	}))
	svc := dynamodb.New(sess)

	// 定义FilterExpression的条件
	filters := []struct {
		AttributeName string
		Operator      string
		AttributeValue interface{}
	}{
		{
			AttributeName: "Age",
			Operator:      ">",
			AttributeValue: 18,
		},
		{
			AttributeName: "City",
			Operator:      "=",
			AttributeValue: "New York",
		},
	}

	// 构建ConditionBuilder对象
	filterBuilder := expression.NewBuilder()
	for _, filter := range filters {
		switch filter.Operator {
		case "=":
			filterBuilder = filterBuilder.WithFilter(expression.Name(filter.AttributeName).Equal(expression.Value(filter.AttributeValue)))
		case ">":
			filterBuilder = filterBuilder.WithFilter(expression.Name(filter.AttributeName).GreaterThan(expression.Value(filter.AttributeValue)))
		case "<":
			filterBuilder = filterBuilder.WithFilter(expression.Name(filter.AttributeName).LessThan(expression.Value(filter.AttributeValue)))
		default:
			fmt.Printf("无效的操作符: %s\n", filter.Operator)
		}
	}

	// 构建完整的FilterExpression
	filter := filterBuilder.Build()

	// 创建DynamoDB查询参数
	params := &dynamodb.ScanInput{
		TableName:                 aws.String("YourTableName"),
		FilterExpression:          filter.Condition(),
		ExpressionAttributeNames:  filter.Names(),
		ExpressionAttributeValues: filter.Values(),
	}

	// 执行DynamoDB查询
	result, err := svc.Scan(params)
	if err != nil {
		fmt.Println(err.Error())
		return
	}

	// 解析查询结果
	items := []YourStruct{}
	err = dynamodbattribute.UnmarshalListOfMaps(result.Items, &items)
	if err != nil {
		fmt.Println(err.Error())
		return
	}

	// 处理查询结果
	for _, item := range items {
		fmt.Printf("Item: %+v\n", item)
	}
}

请确保替换代码中的YourTableName和YourStruct为您的实际表名和表结构。此示例使用了dynamodb.Scan()来执行查询，您可以根据您的需求使用适当的DynamoDB操作，例如dynamodb.Query()或dynamodb.GetItem()。

注意，上述代码示例中使用了github.com/aws/aws-sdk-go/service/dynamodb/expression包，该包提供了构建复杂查询条件的辅助函数。确保在运行代码之前，使用以下命令安装该包：

go get github.com/aws/aws-sdk-go/service/dynamodb/expression

希望这可以帮助到您！