将一个大的tibble分割成几个小的tibble，通过指定一系列的列可以由tidyverse中的select操作，我不知道如何使用map*进行迭代并将它们存储在环境中，有什么好主意吗？

library(tidyverse)

# 
my_tibble <- tibble(
  col1 = rnorm(10),
  col2 = runif(10),
  col3 = letters[1:10],
  col4 = sample(1:100, 10, replace = TRUE),
  col5 = factor(rep(c("A", "B"), 5)),
  col6 = LETTERS[1:10]
)

## assume the combination
grA <- c("col1", "col2")
grB <- c("col3", "col4")
grC <- c("col15", "col6")
cols_list <- list(grA, grB, grC)

## I can get one tibble by select:
my_tibble %>% select(cols_list[[1]])

## but how to use select with map* (rather the baseR) and store it into different objects?
my_tibble %>% map(~select(cols_list))

非常感谢！