How to sync the mentioned users from an event to another?

Hi,

I have an issue with data syncronization. User A can create an event and mention four other user.

Pressing the create button sends them a notification in which they can decide they go or not. If the answear is yes then it will be a new event created for the User B.

The User A event have its uniqe original ID, and I made a new ID (mentioned event ID) property which is the same as the original ID. This new property goes to User B’s, User C’s event as mentioned ID. It may be a connection between the users events. I dont know.

  1. Question: If the answear is yes, how to add the User A’s event’s mentioned users to the User B’s event. The User A is easy to add because he is the sender of the notification.

  2. Question: If User B and User C are said yes, but User D isn’t coming how to delete User D from User B and User C’s event. From User A event it’s easy to delete because User A is the sender of the notification.

  3. Question: Is there any option which makes all this easier? Some way to connect these events and change the mentioned users in every single event?

Thank you all for the answears.
Have a good day,

A poor boy who got stucked at making an app

can you please go deeper in the details how to do it?