Unbounded elements in XML filter

Elastic Stack Logstash
1 
I am getting unbounded elements in  below format and I want to parse specific tags?? (In the below DatasourceDetail may occur 'n' number of times). Like if DataSourceResponseDuration may occur or maynot occur. How to use it in XML filter?

<ser:DataSourceDetail>
        <ser:DataSourceId>1014</ser:DataSourceId>
        <ser:DataSourceOperationID>GetPCMData-ParallelScope</ser:DataSourceOperationID>
        <ser:DataSourceResponseDuration>9347</ser:DataSourceResponseDuration>
        <ser:DataSourceRequestTimeStamp>2016-10-04T08:58:56.129-04:00</ser:DataSourceRequestTimeStamp>
        <ser:DataSourceResponseTimeStamp>2016-10-04T08:59:05.476-04:00</ser:DataSourceResponseTimeStamp>
      </ser:DataSourceDetail>
      <ser:DataSourceDetail xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ass="http://services.dnb.com/AssessmentProductServiceV2.0" xmlns:xte="http://services.dnb.com/XTEDataServiceV1.0" xmlns:soap-env="http://schemas.xmlsoap.org/soap/envelope/">
        <ser:DataSourceId>23585</ser:DataSourceId>
        <ser:DataSourceOperationID>Enhance Corporate Linkage</ser:DataSourceOperationID>
        <ser:DataSourceResultCode>00</ser:DataSourceResultCode>
        <ser:DataSourceResultText>Success</ser:DataSourceResultText>
        <ser:DataSourceResponseDuration>207</ser:DataSourceResponseDuration>
        <ser:DataSourceRequestTimeStamp>2016-10-04T08:58:56.303-04:00</ser:DataSourceRequestTimeStamp>
        <ser:DataSourceResponseTimeStamp>2016-10-04T08:58:56.510-04:00</ser:DataSourceResponseTimeStamp>
      </ser:DataSourceDetail>
      <ser:DataSourceDetail xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ass="http://services.dnb.com/AssessmentProductServiceV2.0" xmlns:xte="http://services.dnb.com/XTEDataServiceV1.0" xmlns:soap-env="http://schemas.xmlsoap.org/soap/envelope/">
        <ser:DataSourceId>19900</ser:DataSourceId>
        <ser:DataSourceOperationID>SLRM</ser:DataSourceOperationID>
        <ser:DataSourceResultCode>CM000</ser:DataSourceResultCode>
        <ser:DataSourceResultText>Success</ser:DataSourceResultText>
        <ser:DataSourceResponseDuration>680</ser:DataSourceResponseDuration>
        <ser:DataSourceRequestTimeStamp>2016-10-04T08:58:56.323-04:00</ser:DataSourceRequestTimeStamp>
        <ser:DataSourceResponseTimeStamp>2016-10-04T08:58:57.003-04:00</ser:DataSourceResponseTimeStamp>
      </ser:DataSourceDetail>