如何使用RedBeanPHP与不同人数的多对多连接创建“组”？

Question

I have 2 tables: employees and groups. Records to add to the group already exist in employees, there is nothing to add. The group for 1 request only one is created. But employees for each request may be different. My $_POSTgets takes an array consisting of employees ids and name of the group: In RedBean documentation an example is given with the known number of records added. But what to do when it is not known how much of the post will come id's?