It sounds like the best option would probably be to use actions. Create a worksheet with a list of the classes. Then, create a worksheet with a list of all the students' names. Then, create a filter action from the class sheet to the student sheet to show only the appropriate students. The following link provides more information on action filters:
Hope this helps!
Thanks for your reply and help, but i think i need it in some other way. I created 5 class (Class 1 to Class 5) and i put it as a filter.When i select Class 1 in the filter, it should show the graph of 10 students of class 1 with their data. Is that possible.?
It sounds like you are there, if you have Class as a dimension and you drag it to the filter shelf you can then make that a filter by right clicking and selecting "Show Quick Filter". Once you have it up it may be defaulting to a list where you can select multiple classes, you may want to keep it this way so you can compare marks across classes, but you can also change that so that you can only select one at a time. In order to do that, click the drop down arrow one the quick filter card (mouse over the top of the card and it should appear) and choose one of the single value options.
Hope that helps.