Thanks for the reply, Jason. I'll look into the VM networking settings. The Linux partition I want access to is on the same internal drive as the MacOS partition that I put the virtual machine on. There are a lot of ways I can accomplish what I want to do, including putting all files I want shared on my Google Drive. What I had been thinking of is using the MacOS more than I have in the past, especially for access to MS Office 2019. One of the big features I use in MS Word, that to my knowledge isn't available on any Linux-native office programs is tracking changes with the changed text in a balloon outside of the document, rather than it being crossed out within the document. This option makes it so much easier to read the changed document, and to see how it will be formatted. LibreOffice and SoftMaker Office don't have this option.
Right now I can use MS Word in Ubuntu through Wine or CrossOver, but the latest version that works reliably is Office 2010. CrossOver support for newer versions is mediocre at best, and still unreliable. There are other options for running a recent version of MS Word within Linux. I could put a Windows or Mac virtual machine on Ubuntu and run Office 2019 from there. For that matter, I could go the other way and put a Ubuntu VM on the Mac OS. There is an advantage to the latter in that all my iMac hardware components run from the Mac OS, but kludges like a sound dongle, an external mic and and usb wifi dongle or PowerLine are required because those internal iMac things do not work from any distro I have tried. But after all the way I've been with Linux, I would find it hard to go back to using the Mac OS as my main OS. Anyway, I'm just looking at options now.