Mapping sequential xml records . . .

You will need to use a custom Xslt.

Here is an example that works with the examples above:

 <?xml version="1.0" encoding="UTF-16" ?>
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform&quot; xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:var="http://schemas.microsoft.com/BizTalk/2003/var&quot; xmlns:userCSharp="http://schemas.microsoft.com/BizTalk/2003/userCSharp&quot; exclude-result-prefixes="msxsl var userCSharp" version="1.0">
  <xsl:output indent = "yes" omit-xml-declaration="yes" method="xml" version="1.0" />
 <xsl:template match="/">
  <xsl:apply-templates select="/Root" />
  </xsl:template>
 <xsl:template match="/Root">
 <Root>
  <xsl:for-each select="Record">
   <Record>
    <xsl:if test="@attrib1">
     <xsl:attribute name="attrib1">
      <xsl:value-of select="@attrib1" />
     </xsl:attribute>
    </xsl:if>
    <xsl:variable name="reset" select="userCSharp:Reset()"/>
    <xsl:for-each select="following-sibling::*">
     <xsl:if test="userCSharp:MapChild(local-name())">
      <NoteToRecord>
       <xsl:if test="@attrib1">
        <xsl:attribute name="attrib1">
         <xsl:value-of select="@attrib1" />
        </xsl:attribute>
       </xsl:if>
      </NoteToRecord>
     </xsl:if>
    </xsl:for-each>
   </Record>
  </xsl:for-each>
 </Root>
 </xsl:template>
<msxsl:script language="C#" implements-prefix="userCSharp">
<![CDATA[
bool done = false;
public void Reset()
{
 done = false;
}
public bool MapChild(string nodename)
{
 if (nodename == "Record")
 {
    done = true;
 }
 return !done;
}
]]>
</msxsl:script>
</xsl:stylesheet>