If you can't see a Candidate's application there a couple of possible reasons:
An incomplete application
The Candidate has started, but not yet completed the assessment. To check if this is the case, open the 'All Applications' table click on the 'Show Incomplete' toggle. This will display all applications not yet complete.
With video interviews, it can occasionally take a few hours for a candidate's videos to complete transcoding ( converting into the different formats to allow replay ).
Until all the videos have been transcoded, the application won't be marked as complete and will appear in the 'Show Incomplete' list.
A Candidates application may have been archived. From the All Applications list click on the 'Show Archived' toggle to display all archived applications.