Screen Sharing to Device with iCloud

Question

Prior to Yosemite, every machine associated with my iCloud ID would show up in the Finder under "Sharing".  If I selected that machine's name, I'd see the shared folders, and be able to activate Screen Sharing directly to that machine with a button click.
Since upgrading to Yosemite, I no longer see these machines available to connect-to.  I've tried disabling and re-enabling "Back to my Mac".  I've also upgraded the Server service running on the host machine I'd planned to connect-to in case that was a factor, but it hasn't resolved the problem.
Anybody know how to get iCloud-linked machines to show up under Sharing in the Finder so I can easily establish Screen Sharing connections?
Thanks

Answer 1

If you changed nothing other than to update your client Mac to Yosemite, what you describe strongly resembles an earlier bug making an encore appearance.
What follows is what I had to say about it roughly a year ago, updated for today. Some of it will be obvious to experienced Mac users so overlook that.
This can be a challenging problem to diagnose. It appears that Mavericks Yosemite has changed something about BTMM resulting in it being less reliable than it was with Mountain Lion Mavericks. It works, but not always, and I have yet to correlate its cause to anything specific.
Here are some possible hints.
Make sure you are using a compatible router. BTMM requires a router that supports NAT Port Mapping Protocol (NAT-PMP) or Universal Plug and Play (UPnP). Most routers will work without any trouble at all, but an Apple AirPort will eliminate any uncertainty.
Review all the steps in OS X: Using and troubleshooting Back to My Mac with your iCloud account
The most useful suggestion may be the simplest:
Toggle Back To My Mac off and back on by deselecting and then reselecting Back To My Mac in iCloud System Preferences.
Sometimes that's all it takes.
You can also try some simple steps with Terminal to verify that your BTMM settings are correct:
dns-sd -B _rfb | grep icloud
That will show the Macs using your iCloud ID advertising screen sharing services. If you get no response, ensure the Sharing services on the Macs you wish to use remotely are configured correctly. Perhaps Mavericks simply reverted their settings during installation, as a "security" measure.
dns-sd -B _afpovertcp will show Macs advertising file sharing services.
To ping your Mac use:
ping6 <macname>.<nnnnnnn>.members.btmm.icloud.com
where <macname> is the name of your Mac and <nnnnnnn> is your Back to My Mac account number. See below. You should get a response from ping6; if there is none then screen or file sharing will not work. If the response times are excessively long then the connection may time out and fail.
The name of your Mac is in System Preferences > Sharing > Computer Name:
Your Back to My Mac account number can be determined with the following
dns-sd -E
It will respond with something like this
Timestamp    Recommended Registration domain
0:43:20.322  Added    (More)              local
0:43:20.322  Added    (More)              icloud.com
                                            - > btmm
                                            - - > members
                                            - - - > 0123123
0:43:20.322  Added                          icloud.com
                                            - > btmm
                                            - - > members
                                            - - - > 987654321
The numbers at the end (0123123 etc) are your BTMM account numbers. Most users will have only one.
^C to terminate each of the above.
Good luck.
An example of the above is as follows. Assuming your iCloud ID is 123456 and the Mac you're trying to connect to is named MyMac the above ping6 command is
ping6 MyMac.123456.members.btmm.icloud.com
You should get a response.
You can also try to login to the remote Mac using ssh. Assuming your login name is telstar that would be
ssh -l telstar MyMac.123456.members.btmm.icloud.com
Both should work regardless of your location, whether both Macs are on the same LAN or separated by thousands of miles makes no difference because they are using iCloud services and not local Bonjour to access the remote machine.
Given that your Mac is not appearing in a Finder Sidebar under "shared" I doubt either of the above will work for you.
Report it to Apple. The problem may be related to the particular model Mac you are using, or not.
That's all I have to offer.