refer to the PDF docs at the paragraph 'Datasets and multiple sitemaps' to manage multiple sitemaps.
If you need to duplicate a separate instance of the 'content' data source, this can be done activating 'Enable multiple 'Content' data sources' in the component configuration so it becomes selectable to be duplicated.
Once you have duplicated the content data source instance you can filter out not needed categories/articles using the exclusions dropdowns. You can use this new 'content' data source for the Google News assigning it to a dataset for multiple sitemaps.
As an alternative you can just use data sources switcher to include/exclude from a certain sitemap type: