“Individuals’s” should never have a repeated “s,” and these examples will show you why:

• Correct: I am the individual’s representative. Anything you want to say to them can be said to me.
• Incorrect: I’m talking to the individuals’s partners right now. I’ll get to the bottom of the situation.
• Correct: Those individuals’ hopes and dreams hang in the balance. Don’t take those away.
• Incorrect: As the individuals’s address was leaked, we need to do something to protect them.