But now I can't boot up in Mac OS (10.14) anymore.

To set macOS as default, use the Startup Disk preference pane in macOS System Preferences, or hold control as you select the disk from Startup Manager (the alt boot menu). Therefore macOS partition won’t show in Boot Camp Control Panel since High Sierra. The latest installer that can be downloaded is 199.8 MB in. Our built-in antivirus scanned this Mac download and rated it as 100% safe. Apple Boot Camp for Mac lies within System Tools, more precisely General. This Mac app is an intellectual property of Apple, Inc. Whether you use an existing partition of the Apple Mac hardware you have or an external disk, I will leave it to you to decide.Apple Boot Camp 3.3 for Mac can be downloaded from our software library for free. But the raw disk VMDK method in the KB is probably your best path forward to achieve what you want. Your host OS X and Fusion versions are quite old as is your intended VM (10.6.8 Snow Leopard). For one thing, High Sierra guests are officially supported only on Fusion 10 and later. There were some quirky steps required for the High Sierra raw disk to get Fusion 8 to run it though these quirks were not needed for the Linux and Windows 10 VM raw disks. For the macOS High Sierra guest, the SSD was from another MacBook Pro that already had High Sierra. For the Windows 10, the raw disk was created and then Windows 10 was installed onto it. For the Linux scenario, the Linux OS was installed/created on a non-Apple laptop and I was able to run the Linux raw disk as a VM within Fusion 8 (in effect a P2V without going through a lengthy P2V conversion process). In all cases, the raw disk was on an external USB SSD. I have used the method specified in the KB to create VMs with Linux, Windows and macOS High Sierra guests in Fusion 8.

Most likely Bootcamp partition VMs are created using this same method.

Look at this KB on how to create a raw disk VMDK for a Fusion VM.

Boot camp mac os x 10.6.8