I don't think all hunter-gatherer societies are the same. Some have a more developed mythology to give meaning to their existences other than just a day-to-day struggle to survive, such as the Aboriginals of Australia, as Doggerland mentioned.
Still, even these people have the beginnings of a belief system surrounding the death of other humans. They don't leave the bodies to rot on the ground but bury them in caves. They hope that they go to the sun, and continue to survive in some form, because they say that they offer prayers that in this "after life" any problems they had in this life will be resolved.
I would like to know if any belongings were buried with the bodies. We know from archaeology that happened with hunter-gatherers. Also, we know that perhaps there were not just celebrations when a big kill was made, but ceremonies to thank the animal, or to pray to the spirit of the animals for success in the hunt. We have records of such things from first encounters with some very primitive North American Native tribes. They weren't all like the Iroquois. Some of the tribes of the Pacific Northwest were basically just hunter-gatherers.
There's definitely a debate as to whether concept/feeling comes first or a word. I've always been of the opinion that the thought comes first, and then a word is created for it. That's why, imo, some words are so culture specific that they're not easily translatable into another language.
For example, Italian has two words for "maybe": forse or magari. Forse operates like "maybe" in English: maybe it will or maybe it won't. Magari is different. It's a maybe laden with hope. Maybe, but if only it would.
Struggimento is another such word. You could translate it in English as yearning, but it means so much more; it's a yearning that causes physical pain, that destroys one.
Sprezzatura is one of my favorites. It was created by Castiglione in the 16th century. It means effortless elegance, and doesn't apply just to clothing. An unexpected, dashing soccer move leading to a goal or even a pass could be an example of sprezzatura.
Or how about meriggiare, which means to seek shelter and rest from the heat of the noonday sun in a place of shade. It's the beginning word of one of my favorite poems by one of my favorite Italian poets.
"Meriggiare pallido e assortopresso un rovente muro d’orto,
ascoltare tra i pruni e gli sterpi
schiocchi di merli, frusci di serpi."
To rest at noon, absorbed and pale,
close to a burning garden wall,
to listen among kindling and thorns
to cries of blackbirds and hiss of serpents.
In the ground's cracks or above the vetch,
to spy on the rows of red ants
that sometimes break and sometimes cross
at the summits of minuscule heaps.
To observe behind the leaves the distant
heartbeat of slivers of sea
while hearing the trembling screech
of cicadas raising from the bald peaks.
And walking into the sun that dazzles
to feel with sad wonder
how all of life and its labor
is in this following along a wall
that has on its top sharp bottle shards."
These hunter-gatherers may feel these emotions. Indeed, by their description of their hope for, but uncertainly about, a place after death where travail and pain will end, I think they do, but they don't have the words to express it. Only with the division of labor and creation of surplus that developed with the Neolithic were there the people with the time to think about these feelings, create words to express them, and even to create mythology to explain man's life and to offer comfort and meaning to it.
Montale is one of the existential poets back at the beginning, because belief systems which gave that meaning to life have shattered.
Another of my favorites: The Second Coming by Yeats
TURNING and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.
Surely some revelation is at hand;
Surely the Second Coming is at hand.
The Second Coming! Hardly are those words out
When a vast image out of i{Spiritus Mundi}
Troubles my sight: somewhere in sands of the desert
A shape with lion body and the head of a man,
A gaze blank and pitiless as the sun,
Is moving its slow thighs, while all about it
Reel shadows of the indignant desert birds.
The darkness drops again; but now I know
That twenty centuries of stony sleep
Were vexed to nightmare by a rocking cradle,
And what rough beast, its hour come round at last
Slouches toward Bethlehem to be born