像这样吗请注意，测试数据采用长格式。

suppressPackageStartupMessages({
  library(ggplot2)
  library(dplyr)
})

df1 %>%
  mutate(
    productName = factor(productName, levels = productName %>% unique()),
    subcat = sub("[[:alpha:]]+", "", subcat)
  ) %>%
  group_by(productName) %>%
  mutate(Group = interaction(subcat, productName, sep = "&")) %>% 
  ggplot(aes(Group, dataNumbers, group = subcat)) +
  geom_col(position = position_dodge(), fill = "steelblue") +
  labs(x = "Model", y = "Data Numbers") +
  guides(x = ggh4x::guide_axis_nested(delim = "&")) +
  theme_bw()

创建于2023-09-10使用reprex v2.0.2

测试数据

set.seed(2023)
Model <- sprintf("Model%s", LETTERS[1:3])
subcat <- sprintf("Spec%d", 1:5)
df1 <- expand.grid(subcat, Model)[2:1]
names(df1) <- c("productName", "subcat")
df1$dataNumbers <- sample(10:20, nrow(df1), TRUE)
df1
#>    productName subcat dataNumbers
#> 1       ModelA  Spec1          14
#> 2       ModelA  Spec2          18
#> 3       ModelA  Spec3          17
#> 4       ModelA  Spec4          12
#> 5       ModelA  Spec5          19
#> 6       ModelB  Spec1          11
#> 7       ModelB  Spec2          10
#> 8       ModelB  Spec3          10
#> 9       ModelB  Spec4          10
#> 10      ModelB  Spec5          10
#> 11      ModelC  Spec1          14
#> 12      ModelC  Spec2          17
#> 13      ModelC  Spec3          11
#> 14      ModelC  Spec4          12
#> 15      ModelC  Spec5          13

创建于2023-09-10使用reprex v2.0.2