The category of the entity posting content on the page(s) you are monitoring. Posts and comments published by the page administrator have the category field associated with them. You can use it to filter for content posted by page managers. You can find out what the page category is when you change the URL of the page from https://www.(...) to http://graph.(...):
- Filter for interactions created by administrators of pages that belong to the given category:
facebook_page.from.category in "Product/service"
Target service: Facebook_Page
Always exists: No