The Vimānavatthu primarily deals with rebirth in deva realms rather than Brahmā worlds.
The brahmaloka (Brahmā-world) is a realm of profound bliss, divided into the realms of subtle materiality (Rūpadhātu) and immateriality (Arūpyadhātu). Inhabitants here dwell in the rapture of meditative absorptions (dhyāna) and live in a state of mental purity. The higher heavens are populated by beings immersed in deep meditation, including non-returners (anāgāmin) who eventually descend to the human realm as omens of future Buddhas. Some beings remain in dreamless sleep for eons. In essence, the inhabitants of the brahmaloka reside in a state of incomparable splendor and peace, far surpassing the divinities of the lower realms (kāmadhātu).
On the other hand, the inhabitants of the Brahmā-world are free from sensual desires.
The Visuddhimagga affirms that being reborn in the Brahmā-world is a consequence of significant virtue combined with meditation.
Another thinks, “I shall enjoy the delights of the Brahmā-world,” and with sense-desire clinging as condition he develops loving-kindness, compassion, gladness, and equanimity. Owing to the fulfilment of the meditative development he is reborn in the Brahmā-world. The kamma that is the cause of his rebirth there is kamma-process becoming, and the rest is as before. (Vsm. VII. 18)
Nonetheless, The lord Buddha taught that all realms, even the highest Brahmā-worlds, are still within saṃsāra and therefore impermanent and ultimately unsatisfactory.
The ruler of the Brahmā-world is Mahābrahmā, the “Great Brahmā.” This term also refers to the highest of the three heavens. In (DN 1), the belief in a creator being arises from the misconception of the first Mahābrahmā, who was reborn in this heaven at the beginning of a world cycle. Misled by his own delusion, he falsely imagined himself to be the creator of all beings born after him in the Brahmā heavens. As the King of the Brahmās, his illusion influenced these beings, causing them to adopt this erroneous belief, which they later propagated on Earth when they were reborn as humans.
Now there arises in him, from his dwelling there so long alone, a dissatisfaction and a longing: “O ! would that other beings might come to join me in this place !” And just then, either because their span of years had passed or their merit was exhausted, other beings fall from the World of Radiance, and appear in the Palace of Brahmā as companions to him, and in all respects like him.
’ On this, brethren, the one who was first reborn thinks thus to himself: " I am Brahmā, the Great Brahmā, the Supreme One, the Mighty, the All-seeing, the Ruler, the Lord of all, the Maker, the Creator, the Chief of all, appointing to each his place, the Ancient of days, the Father of all that are and are to be. These other beings are of my creation. And why is that so ? A while ago I thought, ’ Would that they might come ! ’ And on my mental aspiration, behold the beings came."
'And those beings themselves, too, think thus: " This must be Brahmā, the Great Brahmā, the Supreme, the Mighty, the All-seeing, the Ruler, the Lord of all, the Maker, the Creator, the Chief of all, appointing to each his place, the Ancient of days, the Father of all that are and are to be. And we must have been created by him. And why ? Because, as we see, it was he who was here first, and we came after that."
’ On this, brethren, the one who first came into existence there is of longer life, and more glorious, and more powerful than those who appeared after him. And it might well be, brethren, that some being on his falling from that state, should come hither. And having come hither he might go forth from the household life into the homeless state. And having thus become a recluse he, by reason of ardour of exertion of application of earnestness of careful thought, reaches up to such rapture of heart that, rapt in heart, he calls to mind his last dwelling-place, but not the previous ones. He says to himself: "That illustrious Brahmā, the Great Brahmā, the Supreme One, the Mighty, the All-seeing, the Ruler, the Lord of all, the Maker, the Creator, the Chief of all, appointing to each his place, the Ancient of days, the Father of all that are and are to be, he by whom we were created, he is stedfast immutable eternal, of a nature that knows no change, and he will remain so for ever and ever. But we who were created by him have come hither as being impermanent mutable limited in duration of life.
Rhys Davids, T. W. (trans.). Sacred Books of the Buddhists, Vol. II: Dialogues of the Buddha. Oxford University Press, pp. 31–32.
If you wish to explore this point in more detail, and the entire sutta more broadly, I recommend referring to Ven. Bhikkhu Bodhi (trans.), The All-Embracing Net of Views: The Brahmajāla Sutta and Its Commentaries. If you prefer the BPS edition, it is also available. This work includes a virtuous translation of both the sutta and its commentaries.