BuddyPress.org

@rgauny

This isn’t related to marcoslavorato’s problem.

Your issue can be resolved by defining the BP_ROOT_BLOG.

Read this:

https://codex.buddypress.org/how-to-guides/install-buddypress-on-a-secondary-blog/

Main blog would be mydomain.com

Secondary blog with BP enabled would be xyz.mydomain.com.

This would work only if you plan on having one community and not multiple communities.