The review function is available in LibreOffice for text documents and spreadsheet documents.
When a document has been edited by more than one person, it is possible to merge the edited copies into the original. The only requirement is that the documents differ only and exclusively in the recorded changes - all other original text must be identical.
Open the original document into which you want to merge all copies.
Choose Edit - Track Changes - Merge Document. A file selection dialog appears.
Select the copy of the document from the dialogue. If there have been no subsequent changes to the original document, the copy is merged into the original.
If changes have been made to the original document, an error dialogue appears that informs you that the merge is unsuccessful.
After you merge the documents you will see the recorded changes from the copy in the original document.