OneDrive for Mac not disk space
Now, the only one option is have the OneDrive as a part of your Documents, and this situation full space in our Mac.
In Windows is possible only dowland as a demand, the file that you need to modify.
Would be a good idea develop the same process for Mac, because one of the interesting things about OneDrive is not full space in our laptop.
If you need to have a copy in the hard disk, the OneDrive is less attractive for the users.