The most celebrated commentary on MBH by Neelkanth, "Bhaarat Bhaav Deep" contains this Hari Vansh in it. According to MBH, 2.69.233 it is divided in two Parv - Harivansh Parv and Bhavishya Parv; but the available text consists of 3 sections (called Parv) - Harivansh Parv, Vishnu Parv, and Bhavishya Parv. The whole book attempts to provide the whole history of the Hindu.

(1) The Harivansh Parv describes the creation of cosmos and legendary history of the kings of the Solar and Lunar Dynasties (Soorya Vansh and Chandra Vansh) leading up to the birth of Krishn.
(2) The Vishnu Parv describes all the events from the birth of Krishn to the start of Mahaabhaarat.
(3) The last Parv, Bhavishya Parv, describes a list of future kings and the description of Kali Yug.

This text seems to be based on Panch Lakshan of Puraan, maybe that is why many people call it a Puraan. Its text is complex. It seems to be written before the 1st century BC, because the poet Ashwaghosh quotes a couple of verses attributing them to be of MBH, which are now only found in the Hari Vansh.

(1) Hari Vansh is available in two editions. The vulgate text of the hari Vansh has total of 271 Adhyaaya, divided into 3 Parv - Hari Vansh Parv 55 chapters, Vishnu Parv 81 chapters, and Bhavishya Parv 135 Parv.
(2) The Critical Edition (CE), like the vulgate, the chapters in the CE are also divided into 3 Parv. Hari Vansh chapters 1-45, Vishnu Parv 46-113, and Bhavishya Parv 114-118.

Hari Vansh and Agni Puraan

The 12th chapter of Agni Puraan has described the summary of Hari Vansh. In this Agni describes birth of Krishn in the womb of Devakee. His killing of several Raakshas sent by Kans to kill Him, is also described. Krishn has defeated Jaraasandh and had annexed His kingdom with that of Vasudev.

Jain Harivansh Puraan

There is one Jain Harivansh Puraan too in various languages presenting Krishn's story in Jain tradition. One of the earliest edition is of 783 AD. It is divided into 66 cantos, and contains 12,000 Shlok. The book aims to life of Arishtnemi, the 22nd Teerthankar, According to Jain tradition, Arishtnemi was the first cousin of Krishn.

Yadu Dynasty's description cantos 19-63 - the 32nd canto contains the life of Balaraam. Krishn's story begins from the canto 35. jaraasandh sends his brother and his son to attack Mathuraa, and both of them are killed by Krishn. Arishtnemi is born in Saurya Pur. Jaraasandh siege Mathuraa and Krishn and His people move to Dwaarakaa. Then marriage to Rukminee, abduction of Pradyumn. Then comes the account of Paandav which is quite different from Hindu version. Krishn and Pradyumn meet. Then comes the final combat between Jaraasandh and Krishn with the Kaurav as allies of Jaraasandh and Paandav with Krishn. the war ends with the death of Jaraasandh and the deitification of Krishn as Naaraayan. Then Paandav got to south to Paandu Mathuraa (present Madurai in Tamil Naadu). Arishtnemi attains Arhathood, destruction of Dwaarakaa by Ved Vyaas Jee's curse, the demise of Krishn and Balaraam, then ascent of Paandav to Heaven. Yadu Dynasty continues with Jaratkumaar. It is more like a poetry, than a Puraan