I thought I'd write this out so it is clearer what is needed here. The Manager gets alerted when the trainee completes the training (this is done by the trainer checking the first checkbox in the Netflix interface) - this sets the status also to Completed.
The Manager then gets alerted that it is Completed and Awaiting Approval. If the manager does NOT approve it - the item is reset to In Progress (diagram slightly wrong on this) - If the manager does approve it then status stays as Completed and it is approved.
Discuss this with me if any issues. Applies to non-electronic training only.