https://arstechnica.com/gadgets/2018/08/apple-to-end-support-for-back-to-my-mac-feature-when-macos-mojave-drops/

Mac users began receiving alerts that Apple will end support for its Back to My Mac feature when macOS Mojave comes out this fall. The iCloud feature lets users remotely connect one Mac to another for file transfers and screen sharing. Users could create a network of multiple Macs and access information from any of them on one of the connected devices.