Hi Ahmed,
Thank you for asking.

Yes, It is possible but it is a bad idea. It won’t scale and if you have large number of users, the script will time out.

if you really want to do it, the right way to do it will be using message queues. Most probably, the decision should depend on your number of users.

here is a link of example plugin(without queueing support) that we did for groups:-

https://github.com/sbrajesh/bp-group-activities-notifier

Regards
Brajesh