The location of those locally synced folders from the online storage services, e.g. Microsoft OneDrive Folder, Dropbox Folder, Google Drive folder, could be stored in your user’s library folder which is hidden by default.

To open that folder directly in ACDSee for Mac, please use the following steps:

- Launch Finder and in Finder’s menu bar, click Go | Home
- Click View | Show View Options
- Turn the option to Show Library Folder