That isn't valid XML. XML, by definition, can only have one root element. Below are the requirements to have well formed XML, and the link to the Wikipedia page discussing it. It sounds like you actually have several XML documents.
- The document contains only properly encoded legal Unicode characters
- None of the special syntax characters such as < and & appear except when performing their markup-delineation roles
- The begin, end, and empty-element tags that delimit the elements are correctly nested, with none missing and none overlapping
- The element tags are case-sensitive; the beginning and end tags must match exactly.
- Tag names cannot contain any of the characters !"#$%&'()*+,/;?@[\]^`{|}~, nor a space character, and cannot start with -, ., or a numeric digit.
- A single "root" element contains all the other elements.