Can you have a Multisites within a Multisite Environment?

Hello,

I found a response to this question on this thread:
https://premium.wpmudev.org/forums/topic/is-it-possible-to-create-multisites-within-a-multisite-environment

But found the link referenced in the thread to be couple years old. I am not sure if it is still valid so I am reposting this question.

I am building a website for an organiztion with recurring events that require separate domain for each event. I want to give this organization the ability to run a multisite installation within my multisite installation.

Basically, if I have a domain called "domain1.com," the user would make a subdomain "client.domain1.com" that is domain mapped to "client.com" will the client be able to create a multisite with urls like "event1.client.com" or "client.com/event1".

Thank you for your help!
Calvin