Plot one vs many actual-predicted values scatter plot using R-CodePudding

For a sample dataframe df, pred_value and real_value respectively represent the monthly predicted values and actual values for a variable, and acc_level represents the accuracy level of the predicted values comparing with the actual values for the correspondent month, the smaller the values are, more accurate the predictions result:

df <- structure(list(date = structure(c(1L, 1L, 1L, 1L, 1L, 2L, 2L, 
2L, 2L, 3L, 3L, 3L, 3L), .Label = c("2022/3/31", "2022/4/30", 
"2022/5/31"), class = "factor"), pred_value = c(2721.8, 2721.8, 
2705.5, 2500, 2900.05, 2795.66, 2694.45, 2855.36, 2300, 2799.82, 
2307.36, 2810.71, 3032.91), real_value = c(2736.2, 2736.2, 2736.2, 
2736.2, 2736.2, 2759.98, 2759.98, 2759.98, 2759.98, 3000, 3000, 
3000, 3000), acc_level = c(1L, 1L, 2L, 3L, 3L, 1L, 2L, 2L, 3L, 
2L, 3L, 2L, 1L)), class = "data.frame", row.names = c(NA, -13L
))

Out:

        date pred_value real_value acc_level
1  2022/3/31    2721.80    2736.20         1
2  2022/3/31    2721.80    2736.20         1
3  2022/3/31    2705.50    2736.20         2
4  2022/3/31    2500.00    2736.20         3
5  2022/3/31    2900.05    2736.20         3
6  2022/4/30    2795.66    2759.98         1
7  2022/4/30    2694.45    2759.98         2
8  2022/4/30    2855.36    2759.98         2
9  2022/4/30    2300.00    2759.98         3
10 2022/5/31    2799.82    3000.00         2
11 2022/5/31    2307.36    3000.00         3
12 2022/5/31    2810.71    3000.00         2
13 2022/5/31    3032.91    3000.00         1

I've plotted the predicted values with code below:

library(ggplot2)
ggplot(x, aes(x=date, y=pred_value, color=acc_level))  
  geom_point(size=2, alpha=0.7, position=position_jitter(w=0.1, h=0))  
  theme_bw()

Out:

Beyond what I've done above, if I hope to plot the actual values for each month with red line and red points, how could I do that? Thanks.

Reference: