The chain of nodes you can see hanging on an event will be run in one frame.
If something else calls the same event, their nodes won’t get mixed up, or multitasked. One will run before the other.
The exception to this, is if you use ‘latency’ in the node chain. Then you will get multi tasking problems, because the engine basically puts the rest of the nodes on the back burner the moment it sees latency, and runs something else.
Latency is any node with a small clock in the upper right. Delay, being a good example.
If you are talking about multiplayer specifically ( you didn’t specify that in the tags ), then other rules apply.