このようなXMLファイルを解析する必要があります
1.<?xml version="1.0" encoding="UTF-8"?>
2.<Root>
3.<Record>
4.<in><![CDATA[<?xml version="1.0" encoding="UTF-8"?><XML><Attribute AttrID="A">Test</Attribute>-<Attribute AttrID="B"> <![CDATA[Aap Noot Mies]]> </Attribute>]]></XML></in>
5.<out><![CDATA[]]></out>
6.</Record>
7.</Root>
行番号4の解析中にエラーが発生しますxmlドキュメントのCDATAセクション内のCDATA終了トークン（]]>）をエスケープする方法はありますか？
Your input is not well formed there are several errors I think you need to fix whatever generated that to generate something more like
<?xml version="1.0" encoding="UTF-8"?>
<Root>
<Record>
<in><![CDATA[<?xml version="1.0" encoding="UTF-8"?><!-- - --><XML><Attribute AttrID="A">Test</Attribute>-<Attribute AttrID="B"> <![CDATA[Aap Noot Mies]]<![CDATA[> </Attribute></XML>]]></in>
<out><![CDATA[]]></out>
</Record>
</Root>
Note that the outer CDATA needs <![CDATA[ not <!CDATA[ the first use of ]]> needs to be quoted (for example by stopping and starting the outer CDATA section as here). The outer ]]> needs to be moved after the </XML> so that the end as well as the start of the element is quoted.
That makes the file technically well formed, although elements with name XML (or in general starting with xml in upper or lower case are reserved by the W3C for use in XML related specifications and should not be used in user XML files unless it is a specific element or attribute (such as xmlns defined by the W3C)
In addition I added a (quoted) comment around the dash after the XML declaration as if that CDATA section were extracted and made into an XML document it would make the resulting document non-well formed as only white space or comments and PIs are allowed before the first element.