In order to copy rubrics that you have already created, you can:
Click on “Courses” and select “Content Repository”.
Select “Rubrics”
Click on the three dots drop-down against the rubrics that are to be copied.
Select the “Copy” option highlighted.
Once clicked, there will be a pop-up on the screen with a confirmation message of whether you want to copy the rubrics or not. Click "OK"
Once a rubric is added, you can:
Edit Title.
Edit Course
Add Criteria
Edit Existing Criteria
Save.