How do you say it has been a pleasure working with in Hawaiian?

There isn't a direct, single phrase in Hawaiian that perfectly translates "It has been a pleasure working with you." However, you can express this sentiment using a combination of phrases that convey similar meanings. Here are a few options:

Formal:

* Ua hauʻoli au i ka hana pū ʻana me ʻoe. (This translates to "I have been happy to work with you.")

* Ua maikaʻi loa ka hana pū ʻana me ʻoe. (This translates to "It has been very good working with you.")

* Mahalo nui iā ʻoe no ka hana pū ʻana. (This translates to "Thank you very much for working with me.")

Informal:

* Mahalo nui no ka hana pū ʻana. (This is a more casual way to say "Thank you very much for working with me.")

* Ua ʻoluʻolu ka hana pū ʻana me ʻoe. (This translates to "It has been pleasant working with you.")

The best option for you will depend on your relationship with the person you are speaking to and the context of the situation.