If you want to view the data of another teacher's class, you can learn how below:
Seeing data across more than one of your classes all at once isn't a feature we currently offer.
You can quickly navigate between classes by selecting Your classes and then clicking the class you would like to view.
For MIS-synced schools, you can view all classes within the school by clicking the School classes tab.
You can't see the assignment results from more than one class at once, but you can generate multi-class reports from the reporting page - this can be accessed by clicking reports in the top right.