The problem is to have two charts based on different columns in one chart
example data
set.seed(42) 
data <- data.frame(Id=1:20, 
Q_3_1=sample(1:6, 20, replace=TRUE), 
Q_3_2=sample(1:6, 20, replace=TRUE), 
Level=sample(c("AAAA", "BBBB", "CCCC", "DDDD"), 20, replace=TRUE))
 
    
