Well, I know whar you are meaning to do, as I have my wifes' laptop set up to access a couple of folders on my main system, but that particular configuration is not with in the chromebooks capabilities. Having said that, you might consider getting a usb external hdd. Chromebook will be able to access that. Also, check to see if your version of Chromebook qualifies for the 100gb free cloud storage from google. It will allow you to upload for two years, then after that you can either pay for more time, or just use what you have. You will always be allowed to use whatever you upload, you just won't be able to upload anymore to it. I have an external that I use all the time, plus I am uploading as much as I can.
Have a nice day.