Thank you for that photo, that helps. The most likely reason those eggs are being kicked out is because you do not have a lip on the bottom of that nest. With the movement and scratching of the hens eggs are randomly being kicked out. They are not selecting which eggs get kicked out, it is purely random. There is nothing wrong with those eggs, nothing right about those eggs. It is accidental which ones get pushed out.
Even if those eggs are cold to the touch I'd put them back in the nest and give them a chance. Sometimes they make it, sometimes they don't. But give them a chance.
So what would I do in your situation? First, I'd figure out a way to add a lip across the bottom, maybe using those slots on the sides. I don't know how high that opening is on that nest. If they have six inches clear in height the broody hens can get in and out. I typically have 4" or 5" lips on mine but my nests are very different. A 2" lip would be better than what you have.
Multiple broody hens can often work together to hatch eggs and raise the chicks. It often works. And it is cute! So many people on this forum seem to live for cute. But cute does not always mean safe. As a former poster said, it does not always work. I've had hens fight over a nest when the chicks started pipping. Half of the eggs were destroyed. Since that happened I don't allow multiple broody hens in the same space, let alone on the same nest. I'd break two of those hens from being broody. If you don't know how just ask, we can help.
Sometimes other hens will continue to lay eggs in a broody hen's nest. Since those eggs start incubating later, you have what we call a staggered hatch. When the first chicks that hatch get hungry and thirsty the hen takes them off of the nest to find food and water and abandons the rest. That can be hard on a person, knowing those eggs are developing but are not going to hatch.
Or if the number of eggs continue to increase you may get so many that one hen cannot cover them all. If that happens some get pushed out to cool off and die, then get back under her and another is pushed out to die. You usually do not get good hatches if the number of eggs is more than can be covered.
I do not know how many eggs are in that nest. That may be contributing to some getting pushed out. I agree you should mark the eggs that are in that nest so you know in case other eggs are still being put in there. Then check under them after the others have finished laying for the day and remove any that don't belong. You may need to leave two or even all three hens in there to keep all of the eggs covered and take your chances that they will work together. They often do work together, it is just that sometimes they don't. You never know with living animals. But as a minimum, put a lip on that nest and I'd mark the ones in there now.
Good luck! Let us know how it turns out.