I could only see an option to pick a gdrive file from a drop down list that seemed random (and tedious with no order or search function). Sometimes my file was in the list and sometimes not.
Instead, Google has a tool called Google Drive for Desktop which creates a sync folder on your desktop that makes your gdrive look like Microsoft File Explorer on your desktop. Be careful not to setup synching or you’ll get a full copy of every file on your local hard drive. But for all intents and purposes, you can browse your gdrive easily.
When you point Knime to this drive it can see everything easily.