The VMWare Tools necessary for shared folders do not work.
Use open-vm-tools (https://github.com/vmware/open-vm-tools/wiki/FAQ#installation).
After installing open-vm-tools and rebooting the system, you can find the shared folders at /mnt/hgfs.
That triangle is there because Fusion is not being told by the guest that the "legacy" VMware Tools are installed. That's apparently by design, because open-vm-tools do not indicate that they are installed back to the host The reason for that is that open-vm-tools are not managed by the host. They are managed by the package manager in the guest.Because Fusion isn't told that the "legacy" VMware Tools are installed, it throws that warning triangle. It can be ignored if you have open-vm-tools installed in the guest. I wish they'd fix that, but it's an a