Imagine, I'm the manager of a team with 10 employees and I want to register them for a common training course, for example I want them to take Advanced English training and I want a button to register the 10 employees who are going to take English training, or if I want only 5 employees to take this training course. For this I have 3 sharepoints, one that stores the information about the employees (name, employee id, email,...), another about the information to register the information about the actions (employee name, employee id, action name, action type, action id,...) and another that stores the catalogue of training actions (action name, action id, action type,...). The teams don't all have the same number of employees.

@Jason Smith Can you exemplify the code? I already do the 2 two gallery with checkbox, but i don't do the part of the use of ForAll