Apple seems to have removed the ‘Back to My Mac’ feature with macOS Mojave. The feature is nowhere to be found in the first developer beta of the OS and given its low popularity among Mac users, it is possible that the feature has been silently removed by Apple.
Back to My Mac feature allowed Mac owners to connect to their Mac securely over the internet from another Mac. The feature is a part of iCloud, and it is primarily used for remote file sharing and screen sharing. While the feature sounds handy on paper, it never really worked reliably for most people which is perhaps why Apple is killing it in macOS Mojave.
There are plenty of other services that offer the same set of functionality as Back to my Mac like TeamViewer and they are significantly more reliable as well.
A key reason behind Back to My Mac being unreliable was that it was affected by network configurations that were usually beyond the control of a regular Mac user.
Nonetheless, given how relatively unpopular the feature was among Mac owners, I don’t expect many of them to miss it once Mojave drops later this year.