My approach would be native as despite Dan's efforts, I don't do script.
I would make an Event record and then allow the user to "Quick Select" off a list of employees to add those employees to the Event. by Quick Select, I mean that I have a technique which basically has the user click a button on the Event which creates or edits the current user in a table called User Focus and records the Record ID# of the Event. Then I present the user with a list of employees where the user then can click click click to select which employees attended that Event. Each click will create a record under that Event Record as a child, but does not disturb the report, so that it is quick for the user to continue to quickly select employees. The user may use the normal filter box and dynamic filters on the table report to help narrow down which employees to select.
Then on that report there would be a button to return to the Focus Event.
So now we have our group of employees defined under the Event and now we need to create a record for each employee for each training type that was covered in that event. So then the user would click to see a list of available training courses, and when they click, it would create an employee-training record for each employee for that training course. That would be done with API_RunImport to basically import the employee list for the Focus group into the table of employee-trainings for the Focus Training Course.
If you wanted to work together to get this working on a Go To Meeting session, contact me via the information on my website
QuickBaseCoach.com.
It would probably take a couple or maybe three of hours to get this working.
I know that my approach may feel not normal for someone used to script, but it works well if you get yourself into a low code / no code mindset.