Sounds like you want to record the cited page as well as the pages and have an individual record for each? Do you have multiple “cites” from the one source or a single “cite” from each source?
Usually you assign the cited page when you are creating the citation, thru the “cited pages” field in the edit citation, more menu. Tony points to the knowledgebase link for the how to Add page numbers to citations. There is a bit more info here too on Editing in-text citations.