Combining Multiple LibreOffice Documents into a Single HTML File Using Pandoc

[sevehub]

I have a LibreOffice master document (master.odm) that collects several different LibreOffice documents. I want to use Pandoc to generate a single HTML or another format with a command like:

pandoc.exe -f odt -t html -o .\master.html .\master.odm

However, this results in an HTML file with empty headers for each section. Is there an alternative way to combine multiple LibreOffice documents into a single one?