Once the 'Root level access' permission has been changed for teachers (see District Accounts - Limit Teacher Access)
Teachers now need to be assigned as administrators to the specific groups you (as the district level admin) would like them to access.
Create a new school group and make a teacher an admin of the group
Sign in to your organization account, then click on "Create new group"
Enter a name for the new group:
Then click on the 'Administrators' tab:
Click on 'Add admin'
Enter the name or email address of the teacher who you would like to give access to this account, then select the account from the drop down list:
Then press 'Add'
Then click on 'Create'
The new group will be created and the teacher will be assigned as administrator of this group:
When the teacher next logs in they will be able to see the 'Example School 1' group, and any users that are in this group.
They will also be able to add new students directly to this group within the organization account. Additionally, they can create subgroups (e.g., for different classes within their school) beneath this group.