I have multiple Google Accounts: one personal, one for a business I run, another at a non-profit I work at. Since I can only sign into Drive as one user for the purposes of the desktop syncing app (on Mac), I want to share the contents of the latter two accounts with my personal account such that they appear as folders there. (I can then add them to My Drive and get access to them via Finder.)
This is a duplicate of this question. However, that question has not been fully answered. There is a suggestion that it is possible to change a setting in order to make this happen, however there is no description of how to find that setting. Other sources online (e.g. in response to this SO question) have suggested sharing every single file and folder individually (perhaps by using the API to automate the process), however this is no use since I will be adding new files all the time. For now my solution is to put everything within a folder (i.e. no files or other folders at root level) and then share that folder. However, this makes the experience of using the web version of Drive rather frustrating, since I need to click down into that dummy folder every time I go to Drive.