In the polyamorous community, jealousy is still a thing that exists. The main method of tackling this has always been communication, expressing to each other how things make you feel and try to find a solution to overcome that.

Mind you you also have to be willing to change things you might be doing in order for this system to work, because otherwise you are asking your partners something you yourself are not willing to do. Multiple people can't function in a relationship if only a few of them are doing all the work. Not in a healthy one at least.

But yeah, just talk with them. It brings you closer, it makes you feel safer, it shows each other trust, and it can easily fix issues you might be going through. My partner and I have been going through a lot of mental health stuff lately and every time we fight it turns into a conversation trying to understand why the fight happened, which often turns into a lot of introspection and healing over past trauma. We used to think fights destroy relationships but we changed how we fight and now it's more like charged healing and bonding.