There are a number of ways you can differentiate between your students on Mathspace to help individualise their learning experience:
You can create different classes for different groups in your class and assign different tasks to each group.
You may also add different curricula for different groups of students.
You can set a target mastery accordingly to the class for each class.
You can create custom tasks and assign them to individual students or groups of students. This means you can which students receive which questions, so they are always working on content that is appropriate for them.