Greetings, I want to install the main multisite

Greetings,

I want to install the main multisite at domain.com/blog and all the other sites would be at domain.com/blog/site1/...

Is this possible?

I've installed it but the links in the articles of the root blog are repeting the folder:
domain.com/blog/blog/name-of-article/

I've try to change the wp-config, but couldn't solve the problem.

Can anyone please help me solve this?

Thanks,
Diogo Gomes