Adding copies to create grouped events and adding additional repetitions of an event seem very similar. But they are different, and can even be used together. In this example, you can see how to create an event and simultaneous two additional copies of the same event.
This event will be seen on Fridays, Saturdays and Sunday from November 26th, 2021 until December 31st 2021.
Most of the event creation process is standard; fill in all of the event information you need.
In Date and Time, fill in the time for the original event and make two copies.

In Repetition Pattern, set the frequenty, period, and end date for the repetition sequence.
- Frequency: 1.
- Period: Weekly.
- Repeat Until: 2021-12-31.

You can now publish the event.
Here is the front end December calendar view:

The last weekend was the 26th of December. If I choose to do so I could add another event on Friday the 31st of December.
See the following links for additional information on Adding Event Copies and Repetition Patterns.