I think this proceeds from a misunderstanding of what guerilla forces actually are.
They do not hide amongst the civilian population. They arise from the civilian population.
Unlike regular soldiery which is also drawn from the civilian population, there are no typical organisational trappings or physical structures for guerillas.
Guerilla fighters arise typically when states mal-administer and oppress a civilian population.
It's become quite common from the 20th century for these guerilla forces to arise, because technological differences have made it often easy for one side to attack the regular forces of another, often from afar.
So nowadays, there often arises a situation where a population is seriously oppressed, but also denuded of the regular forces which they would have formed and used to respond to that kind of attack in the historical past.
In the late 19th century and early 20th century, the first reaction of powerful empires with these asymmetrical technologies was to treat the entire civilian population as the enemy and pummel them.
What they found is that this has two effects.
Firstly, it releases even more dangerous forces from the civilian population in question. Such that even more civilians are mobilised into the guerilla warfare, often with a determination and fearlessness that eclipses what states with regular forces are capable of marshalling in response, and in unexpected ways that render regular forces either ineffective, or which causes (what's nowadays termed...) moral injury to those regular forces (and has consequences both for their discipline in regular service, and for their broader society when they return home).
Vietnam is an example of this (admittedly a later example from the USA, when European empires had already learned their lesson in their colonial possessions).
Secondly, exterminations of the civilian population in part or whole often not only end up consuming serious numbers of regular forces, or at least consuming serious economic resources, but also provokes hostile combinations of remaining enemies that the oppressor had previously encountered (or even successfully promoted and maintained) in a divided or passive condition.
Nazi Germany is an example of this.
For both of the above reasons, strong states have tried to encode laws against assaulting civilian populations, because it always seems to engulf and defeat them for reasons each new generation of regular officers and politicians cannot grasp.
The behaviour of the guerillas defies all their experience of how civilians think and behave in peaceful, wealthy environments (including how civilians react to policemen or soldiers, when those policemen or soldiers threaten force), and how easily regular professional forces collapse once you destroy their materiel and commanding structures.
By contrast, guerillas never seem to collapse, and no matter how high the bodies mount there seems to be another fearless guerilla ready to die in order to deal damage to the oppressing side - even women and children are mobilised.
So the straightforward answer is, yes, Hamas guerillas "hide" in the population, because populations naturally produce and host guerillas from their own number under conditions of oppression.
I should say, the oppression to which I refer are the objective conditions of Gaza. I'm not expressing a position on the political causes. I'm suggesting that guerillas arise from the objective conditions of oppression, regardless of any political rights or wrongs of why those oppressive conditions may have arisen.
Israel is correct in how it analyses the entire Gazan population as being a collective threat, with no real differentiation between civilian and fighter.
But it's proposed solution always falls into one of the two follies I mention above. It will either pummel Gaza and release more dangerous forces, or it will attempt extermination and unite the Arab world whilst alienating it's Western liberal patron states.
Biden is busy trying to work them into only option 1 (pummeling) instead of option 2 (extermination), since the dangerous forces released under option 1 would overwhelm Israel alone, but it is still a manageable problem for Israel's patrons collectively who can allocate more economic resources to reinforce Israel.
Option 2 would cause internal political problems for the patrons, and possibly bring them into sudden confrontation with an un-cowable Arab alliance, which is why they won't allow it.