在这种情况下，我建议将数据子集化，而不是旋转：

ggplot(data, aes(x = group, y = value, fill = condition)) +
  geom_col(data = filter(data, Source == "Simulated"),
           position = position_dodge()) +
  geom_point(
    data = filter(data, Source == "Experimental"),
    aes(group = condition),
    position = position_dodge(width = 1)
  )

利用这些数据

data = read.table(text = 'group     condition   value   Source
A   Health  1.0000000   Simulated
B   Health  1.0000000   Simulated
C   Health  1.0000000   Simulated
A   Disease     0.4589925   Simulated
B   Disease     1.4905422   Simulated
C   Disease     1.3422035   Simulated
A   Health  1.0000000   Experimental
B   Health  1.0000000   Experimental
C   Health  1.0000000   Experimental
A   Disease     0.5158371   Experimental
A   Disease     0.7559055   Experimental
B   Disease     1.4153005   Experimental
B   Disease     1.4000000   Experimental
C   Disease     1.3300971   Experimental
C   Disease     1.0000000   Experimental', header = T)