From the Hilton Honors terms and conditions:
A Member may earn Base Points for up to four rooms per stay ("Earning Rooms") if all eligible charges for Earning Rooms are paid on one folio. Base Points will be earned for all eligible folio charges incurred on Earning Rooms. The term "eligible folio charges" is defined below. Bonus Points issued on Base Points, including tier bonuses (20%, 80% or 100%, depending on Member tier), Bonus Points earned through double or triple Base Point promotions, will apply to the total Base Point credit earned for Earning Rooms. For any other bonuses, including Hilton Honors Marketing Partner Bonus Points and other promotional bonuses (e.g. promotional miles), Bonus Points will be awarded on one room only. For purposes of obtaining tier status, a Member will receive stay and night credit for one room only.
You will not receive additional night and stay credits for these additional rooms. You haven't said where these stays are occurring but with your Diamond status you are only entitled to breakfast or the F&B credit for you and one other person booked in the same room.