Divine mother is seen as a group of eight in many ways
1. Panchabhootaani chandrarka vaatmeeti munipungava
Murthi rashta shiva syahur devadevasya dheematah
Aatmaa tasyaam shamee murthy ryajamaanahvayaa paraa
The five elements, Sun, Moon and a somayaji performing Yagna are Ashtamurthis
2. Bhava, Sharwva, Eshaana, Pashupathi, Rudra, Ugra, Bheema, Mahadeva
3. Bhagavadgeeta:
Bhoomiraapo nalo vaayuh Kham mano buddhi revacha
Ahankaara iteeyam me bhinna prakruti rashtagaa
The five elements, the mind, the intellect and the ego
4. Shakti rahasyam:
Lakshmirmedha dhara pushti gouri tushti prahba dhruti
Etabhih paahi tanu rashtaabhi rmam saraswati
Lakshmi, Medha, Dhara, Pushti, Gouri, Tushti, Prabha, Dhruti
5. Yoga Shastram:
Guna bhedaatma murthih: Ashtadha parikeertitah
Jeevatma chantaraatma cha paramaatma cha nirmalah
Shuddhaatma Gnaana roopaatma mahatma saptmasmrutah
Ashtama steshu Bhootaatme Twastatmaanah prakeetitah
Jeevatma, Antaratma, Paramatma, Nirmalatma, Shuddhatma, Gnaanaroopaatma, Mahatma, Bhootatma
6. Vishnu puranam:
Suryudu, Jalamu, Prithivi, Agni, Vayu, Akaasha, A Brahmin performing a sacred ritual, Moon
Their better halves in the same order
Suvarchala, Soma, Sukeshi, Swaha, Parashiva, Diti, Deeksha, Rohini
Their sons in the same order
Shani, Shukra, Lohitanga, Jeeva, Skanda, Swarga, Santana, Budha
7. Anangakusuma, Anangamekhala, Anangamadhana, Anangamadanaatura, Anangarekha, Anangavegini, Anangankusha, Ananga maalini
8. Brahmi, Mahsewari, Koumaari, Vaishnawi, Varaahi, Maahendri, Chamunda, Mahalakshmi
9. Gnanendriyaalu, Karmendriyaalu, Ahankaara chatushtayam, Prana panchakam, Bhoota panchakam, kaamamu, karma, avidya
Like this there are many octets that are seen as forms of Divine Mother
10 Kaadividya, Haadividya, Sankhyavidya, Bhoomavidya. When considered along with their better halves become eight.