Time Machine share not found in Time Machine Settings in Yosemite

I can not get the default settings in MyBook Live to show in my Time Machine settings.

In the Settings / System / Mac Backup, I have enabled the Time Machine settings and selected a share and put a 1Tb limit on my 2 Tb drive.  On the back, I can also use Finder to SMB to the share selected.

But in the mac Time Machine preferences, the share is never shown on the list of drives.


I recommend you map the share on the computer.

What does “map the share” mean?