WordPress MU Domain Mapping works with subfolder?

You don’t.

If you want to map a domain, put WordPress in /, not /blog/.

Thanks for quick response. I might be confused, but I read the discussion here: https://www.ads-software.com/support/topic/plugin-wordpress-mu-domain-mapping-domain-mapping-ms-subdirectory-installations
and it said about park? Can this really be tweaked or none to zero change?

That’s not the same thing.

You can map a subfolder install (i.e. domain.com/sitename)

You cannot map a sub-subfolder install (i.e. domain.com/blog/sitename)

That’s just a problem with how webservers work.

I have also looked everywhere and seem to find no solution, but I found another paid plugin: https://premium.wpmudev.org/project/domain-mapping

Do you know if this plugin can do the job? If not, how do you recommend me moving it to root where I already have my main site installed?

Sorry to ask many questions, but I am pretty new to dis multisite.

Where is WordPress installed?

Where is the MAIN WordPress site?

If WordPress is installed in domain.com/ you’re fine.

If you installed it so the main site is domain.com/blog/, then no plugin will help you.

my main site already installed at mydomain.com and the multi site is at mydomain.com/blog

You’re doing this wrong.

If your MAIN site is mydomain.com, then you turn on Multisite there and build child sites off mydomain.com directly. You do not make a second installation of WP to run as Multisite. Defeats the purpose ??

Thanks a lot for all answers. Yeah, I kinda crazy about this ??
Will just convert my main site to mutlisite then.

Again, thank you Ipstenu.