Here is what you need to do in order to link multiple properties or Analytics accounts at once:
1. In your workspace click Data Sources -> Add a New Data Source.
2. Hit the Connect button in the Google Analytics section.
3. Navigate to the account you want to link.
4. Choose the views you want to connect. (You can select multiple views from different properties by using the checkbox feature)
Have trouble linking your Google Analytics account? Contact [email protected]!