I agree it's probably not necessary, but it might bring peace-of-mind to contact the hotel a week or so in advance to let them know you have multiple reservations and you'd like not to switch rooms. A decent Reservations/Front Office Manager will go ahead and assign those string of reservations to a specific room.

The hotel has their own website (separate from the main Hilton one) that lists an email for their Reservations Office.

https://www.hiltonhawaiianvillage.com/contact-us

Another option is to use the fax number that's show at the bottom of that page. I'm a big fan of old-school faxing, as faxes are harder for employees to ignore when compared to email. They are great for simple requests that this one.

(If you don't have access to a real fax machine, there are a number of websites that will send a 1-2 page fax electronically for free.)