(DB) "Son of Man" that figure was named, alluding to his origins in the divine figure named "one like a Son of Man/a human being" in Dani'el!
In other words, a simile, a G d who looks like a human being (literally Son of Man) has become the name for that G d, who is now called "Son of Man," a reference to his human-appearing 'divinity'.
The only plausible explanation of the "Son of Man" is that of Leo Baeck, the great Jewish theologian & scholar of the last century, who wrote: "Whenever in later works 'that Son of Man,' 'this Son of Man' or 'the Son of Man' is mentioned, it is the quotation from Dani'el/Daniël that is speaking!"
This dual background explains much of the complexity of the traditions about Yeshu/Yeshua/Yehoshua/Jesus?! It is no wonder, then, that when a man came who claimed & appeared in various ways to fit these characteristics, many Jews believed he was precisely the one whom they expected. (It's also no wonder that many were much more skeptical!?)
There are many variations of traditions about this figure in the Gospels themselves & in other Jewish texts. Some Jews had been expecting this Redeemer to be a human exalted to the state of divinity, while others were expecting a divinity to come down to earth & "take on human form"; some believers ('supposers'

in/about 'Jesus' believed the 'Christ' had been born as an ordinary human & then exalted to divine status, while others believed/guessed him to have been a divinity who came 'down to earth'!
Either way, we end up with a doubled godhead & a human/divine combination as the expected Redeemer. (In these ideas lie the seed that would eventually grow into doctrines of the supposed/fabricated Trinity & incarnation in all of their later variations, variations that are inflected as well by Greek philosophical thinking; the seeds, however, wer sown by Jewish apocalyptic writings!)!
These serious connections between older pre-Yeshu ideas of the Messiah/Christ are those that Yeshua would claim for himself are thus very intimate indeed! Who is THE Son of Man? Ye(ho)shu(a) famously refers to himself by that mysterious term "The Son of Man." And since than real oceans of ink & forests of trees have given their substance so that human could continue to argue about where this term came from and what it means.
(To be sure, the person of the king had a sacralized quality, & moreover, as we see for instance in the case of Sja'ul himself and Shmu'el, even an ecstatic or prophetic measure: was Sha'ul among the prophets?) Regarding it's meaning, some say it refers to Jesus' human nature, while others say it refers to his 'divine' nature.
Anyway, again, we'll see or we won't. Take your pick while you still can. Or don't.