You can only sync one file from one computer
As you have linked your file from your laptop, you cannot also link it to your desktop
You can make a copy of your file, rename it and create a second linked tree, but then there is an issue about keeping these files in sync as well.
The developers are well aware of this issue and maybe in a future release multiple linking will be possible. But at the moment it is not supported.
Given the amount of work and time to get link and sync working between one file and one computer, I imagine there would be a lot more work to get multiple links to sync.