Kroṣṭā (son of Yadu) had two wives - Gāndhārī & Mādrī. Gāndhārī's son was Anamitra. And Mādrī had two sons- Yudhājit and Devamīḍhuṣa (Harivaṁśa 1.34.1-2). Anamitra's son was Śini & Śini's son was Satyaka, who had Śaineya as upanāma. Satyaka's son was Sātyaki, who had upanāma Yuyudhāna. (Harivaṁśa 1.34.29-30). Devamīḍhuṣa (who was the son of Kroṣṭā & Mādrī) had a son named Śūra. Among the many children of Śūra with Bhojarājakumārī, the eldest son was Vasudeva, who had upanāma Ānakadundubhi. (Harivaṁśa 1.34.17-18).
With his wife Devakī, Vasudeva borne Kṛṣṇa. (Harivaṁśa 1.35.7).
Therefore, Sātyaki was a third cousin of Kṛṣṇa, and both of their closest common ancestor was their great-great grandfather Kroṣṭā, one of the many sons of Yadu. (Harivaṁśa 1.33.1).
Above is the list from Harivaṁśa, which is pretty small compared to say list from Bhāgavata.
Below list from Yadu to Kṛṣṇa & Sātyaki would be detailed from Bhāgavata Purāṇa (9.23-24).
Yadu had 4 sons - Sahasrajit, Kroṣṭā, Nala, & Ripu. Since both Kṛṣṇa and Sātyaki are descended from Kroṣṭā, so only his lineage would be mentioned here, this would be followed later too.
Kroṣṭā → Vṛjinavān → Śvāhi → Ruśeku, Citraratha → Śaśabindu → Pṛthuśravas → Dharma → Uśanas → Rucaka → Jyāmagha → Vidarbha → Kratha → Kunti → Dhṛṣṭi → Nivṛti → Darśāha → Vyoma → Jīmūta → Vikṛti → Bhīmaratha → Navaratha → Daśaratha → Śakuni → Karambhi → Devarāta → Devakṣatra → Madhu → Kuruvaśa → Anu → Puruhotra → Āyu → Sātvata → Vṛṣṇi I → Yudhājit → Anamitra (sibling of Śini I)
Anamitra had three sons, two of which are important to us viz. Śini II and Vṛṣṇi II.
Anamitra → Śini II → Satyaka → Yuyudhāna (Sātyaki)
Anamitra → Vṛṣṇi II → Citraratha → Vidūratha → Śūra I → Bhajamāna → Śini III → Syayambhoja → Hṛdīka → Devamīḍha → Śūra II → Vasudeva → Kṛṣṇa
Based on this Yādava lineage mentioned in Bhāgavata Purāṇa (9.23-24), Sātyaki is grand-grand..... uncle of Kṛṣṇa, both of their closest common ancestor being Anamitra.
