Sample Data:
Exam Required Held
Maths A3 A2
Science A2 A3
English A1 A1
Social A3 A2
Test1 A1 A1
Test2 A1 NA
Sample Visualization: 
Note:
I want A1,A2 and A3 as values only so that I can take count of Required and held in the same bar. Can someone help me on this?