Spiritual Hierarchy

Pantheon

At the top sit the celestial deities (Thiên Thần), Ngọc Hoàng or the Jade Emperor (Orginially a Vietnamese god, later linked to the Jade Emperor by Taoist influence) is believed to be the supreme ruler of Heaven. In folk tales, he regularly interacts with human affairs by punishing the evil and rewarding the good. Keep in mind that the pantheon as a whole is just a loose definition and varies by tradition.

Thượng Đế

Thượng Đế or the Heavenly Lord is also a celestial diety and responsible for overseeing the balance of the universe. Thượng Đế is sometimes compared to the Jade Emperor, but other times Thượng Đế is portrayed as less of a personified diety and more of an idea, like divine right. Less directly worshipped, more referenced in oaths and teachings.

Buddhist Figures

In some traditions, various figures from Mahayana Buddhism are also worshipped and seen as a part of the 'highest tier' or the celestial deities. Deities include Phật A Di Đà (Amitabha Buddha), Quan Thế Âm Bồ Tát (Avalokiteshvara/Guanyin) though often portrayed as a woman (Quan Âm) in Vietnam and Đức Phật Thích Ca (Shakyamuni Buddha, the historical Buddha).

Nam Tào and Bắc Đẩu

There are also Nam Tào & Bắc Đẩu. Nam Tào records the births while Bắc Đẩu records deaths under employment of the Jade Emperor. While Nam Tào records the exact year, month, day and hour of birth, Bắc Đẩu does the same for the time of death. Bắc Đẩu observes their karma and might choose to extend or shorten their lifespan. After death, they're sent to the underworld.

I say 'might choose' because Bắc Đẩu extending a lifespan is not guaranteed, though it can be invoked through ceremonies or other deities pleading for mercy in the name of a mortal life. According to some folk tales, some humans have managed to alter their ledger though the repercussions are heavy if found out, of course.

You also have Văn Xương Đế Quân, the God of literature and examinations who is worshipped by students and given offerings for academic performance. Sometimes, these three are included in the middle tier but it depends.

Middle Tier

The Middle Tier consists out of the nature dieties and the Four Palaces (Tứ Phủ), domain of the four Mother Goddesses, specific to the Đạo Mẫu tradition. They're often worshipped in rituals (unlike, say, the Jade Emperor who's much less frequently worshipped directly) and in daily prayers. They're not as supreme as the celestial dieties, but still hold influence over daily life and the natural world.

Nature Spirits/Deities

Includes figures like the Sky God (The Sky God), ruler of the weather, Thổ Công/Thần Đất (Earth God) and Bà Thủy (Lady of the Waters) among others. These deities are often prayed to for higher crop yields or for other reasons, for example a logger would pay their respects to the Mountain God (protector of forests) before entering a forest for, for example luck.

Tứ Phủ

Tứ Phủ refers to the Four Palaces, worshipped in Đạo Mẫu. Each palace is governed by their own Mother Goddess, them being Mẫu Thượng Thiên, her palace being Thiên Phủ (Heaven), Mẫu Thượng Ngàn (Nhạc Phủ or forests), Mẫu Thoải (Thoải Phủ or Water) and Mẫu Địa (Địa Phủ or Earth). Each Goddess has her own set of spirit servants who serve them and are worshipped through spirit medium (hầu đồng) where mediums channel the deities through ceremony.

Village Deities

In Vietnamese referred to as Thành Hoàng, each village (traditionally) has their own Thành Hoàng oftentimes an important village elder, local spirit or a historical hero. These deities protect the village from (natural) disasters, evil forces and epidemics. They are celebrated annually in festivals (lễ hội) where offerings, performances and more are made as tribute.