How to mark any exercise as completed from the admin side?

Click on the right arrow button across the group’s name as shown below.

On the Content tab, click on the Manage button across the Assessment content. 

Click on the Settings icon . As the drop-down window opens, click on the "Mark exercise as completed" feature.

Select for which participant you want to mark an exercise as completed.

A pop-up window appears asking to confirm to mark the exercise as completed for a particular participant.

Click on Confirm.