admin/managerepository/remotemoodle
From MoodleDocs
Introduction
The Moodle Repository plugin allows users to browse a foreign Moodle site in the File Picker. The user sees all the files/data he has access to there and is able to choose them.
Network settings
You need to setup a Moodle peer. Please follow the tutorial. In this tutorial, at step 2.2 and 2.3, you also have to enable Remote Moodle Repository options.
Plugin Administration
Create an instance and select the peer you've just set up.
Test that it works
Open a file picker and test that you can retrieve a file from the remote Moodle.