Currently, Classlist does not allow for a user to be assigned to multiple administrator roles though this is planned to be amended in a future patch.
For now, assign yourself to the highest 'rank' status and add the secondary status as a 'Label'. As an example, this will let other parents know that you are the Class Rep for Form 3A while still keeping all of the functionality of the higher role.
In terms of functionality the roles act in the following order (highest first):
- Class Rep
- Community Rep