无法对嵌套 data.frame 中的列进行子集化

我有数据.框架，其中包含多个字符列，但也包含一个数据.框架因此，我有一个数据.框在我的数据里面.框架我的目标是将一个字符列与嵌套数据中的一个列一起子集.框架但是，每当我试图按名称将嵌套列子集时，它都会声明它不存在.你可以看到数据.框在这里:

df = structure(
  list(
    `$id` = c("21", "22", "23"),
    Id = c("159347",
           "161863", "22646"),
    Name = c("159347", "161863", "22646"),
    SumPeriod = structure(
      list(
        AccPeriodBasTwrAtMarketPrice = c(0.0969367972082358, 0.537983489472227,-0.107066381156318),
        AccPeriodLocTwrAtMarketPrice = c(0.0969367972082358,
                                         0.537983489472227,-0.107066381156318),
        BopDate = c(
          "2022-02-28T00:00:00",
          "2022-02-28T00:00:00",
          "2022-02-28T00:00:00"
        ),
        BopBasHoldingValueAtMarketPrice = c(7592266.52,
                                            5135960.59, 7166815.5),
        BopBasInterestAccrual = c(0, 0, 0),
        EopDate = c(
          "2022-02-28T00:00:00",
          "2022-02-28T00:00:00",
          "2022-02-28T00:00:00"
        ),
        EopBasHoldingValueAtMarketPrice = c(7599626.22,
                                            5163591.21, 7159142.25),
        EopBasInterestAccrual = c(0, 0,
                                  0),
        AccPeriodBasTwrAtExposureValue = c(0.0969367972082358,
                                           0.537983489472227,-0.107066381156318),
        AccPeriodLocTwrAtExposureValue = c(0.0969367972082358,
                                           0.537983489472227,-0.107066381156318),
        AccBasIrr = c(0.0969367972082358,
                      0.537983489472227,-0.107066381156318),
        AccLocIrr = c(0.096936797208258,
                      0.537983489472227,-0.107066381156318),
        AccBasMwr = c(0.0484449181280957,
                      0.268270120259021,-0.0535618639528656),
        PeriodBasIrr = c(0.0969367972082358,
                         0.537983489472227,-0.107066381156318),
        PeriodLocIrr = c(0.096936797208258,
                         0.537983489472227,-0.107066381156318),
        PeriodBasTwrAtMarketPrice = c(0.0969367972082358,
                                      0.537983489472227,-0.107066381156318),
        PeriodLocTwrAtMarketPrice = c(0.0969367972082358,
                                      0.537983489472227,-0.107066381156318),
        PeriodBasTwrDeposit = c(0,
                                0, 0),
        PeriodBasTwrWithdrawal = c(0, 0, 0),
        PeriodBasTwrDepositWithdrawal = c(0,
                                          0, 0),
        PeriodBasTwrDividendTax = c(0, 0, 0),
        PeriodBasTwr = c(7359.70000000112,
                         27630.6200000001,-7673.25),
        PeriodBasMwr = c(0.0484449181280957,
                         0.268270120259021,-0.0535618639528656),
        BenchmarkCalcType = c(
          "BenchmarkNotCalculated",
          "BenchmarkNotCalculated",
          "BenchmarkNotCalculated"
        ),
        EopBenchmarkName = c("",
                             "", ""),
        AccBasBenchmarkReturnPct = c(0, 0, 0),
        PeriodBasBenchmarkReturnPct = c(0,
                                        0, 0)
      ),
      class = "data.frame",
      row.names = c(NA, 3L)
    ),
    Series = list(
      structure(
        list(
          AccPeriodBasTwrAtMarketPrice = 0.0969367972082358,
          AccPeriodLocTwrAtMarketPrice = 0.0969367972082358,
          BopDate = "2022-02-28T00:00:00",
          BopBasHoldingValueAtMarketPrice = 7592266.52,
          BopBasInterestAccrual = 0,
          EopDate = "2022-02-28T00:00:00",
          EopBasHoldingValueAtMarketPrice = 7599626.22,
          EopBasInterestAccrual = 0,
          AccPeriodBasTwrAtExposureValue = 0.0969367972082358,
          AccPeriodLocTwrAtExposureValue = 0.0969367972082358,
          AccBasIrr = 0,
          AccLocIrr = 0,
          AccBasMwr = 0.0968429207825055,
          PeriodBasIrr = 0,
          PeriodLocIrr = 0,
          PeriodBasTwrAtMarketPrice = 0.0969367972082358,
          PeriodLocTwrAtMarketPrice = 0.0969367972082358,
          PeriodBasTwrDeposit = 0,
          PeriodBasTwrWithdrawal = 0,
          PeriodBasTwrDepositWithdrawal = 0,
          PeriodBasTwrDividendTax = 0,
          PeriodBasTwr = 7359.70000000112,
          PeriodBasMwr = 0.0484449181280957,
          BenchmarkCalcType = "BenchmarkNotCalculated",
          EopBenchmarkName = "",
          AccBasBenchmarkReturnPct = 0,
          PeriodBasBenchmarkReturnPct = 0
        ),
        class = "data.frame",
        row.names = 1L
      ),
      structure(
        list(
          AccPeriodBasTwrAtMarketPrice = 0.537983489472227,
          AccPeriodLocTwrAtMarketPrice = 0.537983489472227,
          BopDate = "2022-02-28T00:00:00",
          BopBasHoldingValueAtMarketPrice = 5135960.59,
          BopBasInterestAccrual = 0,
          EopDate = "2022-02-28T00:00:00",
          EopBasHoldingValueAtMarketPrice = 5163591.21,
          EopBasInterestAccrual = 0,
          AccPeriodBasTwrAtExposureValue = 0.537983489472227,
          AccPeriodLocTwrAtExposureValue = 0.537983489472227,
          AccBasIrr = 0,
          AccLocIrr = 0,
          AccBasMwr = 0.535104714457055,
          PeriodBasIrr = 0,
          PeriodLocIrr = 0,
          PeriodBasTwrAtMarketPrice = 0.537983489472227,
          PeriodLocTwrAtMarketPrice = 0.537983489472227,
          PeriodBasTwrDeposit = 0,
          PeriodBasTwrWithdrawal = 0,
          PeriodBasTwrDepositWithdrawal = 0,
          PeriodBasTwrDividendTax = 0,
          PeriodBasTwr = 27630.6200000001,
          PeriodBasMwr = 0.26827012025902,
          BenchmarkCalcType = "BenchmarkNotCalculated",
          EopBenchmarkName = "",
          AccBasBenchmarkReturnPct = 0,
          PeriodBasBenchmarkReturnPct = 0
        ),
        class = "data.frame",
        row.names = 1L
      ),
      structure(
        list(
          AccPeriodBasTwrAtMarketPrice = -0.107066381156318,
          AccPeriodLocTwrAtMarketPrice = -0.107066381156318,
          BopDate = "2022-02-28T00:00:00",
          BopBasHoldingValueAtMarketPrice = 7166815.5,
          BopBasInterestAccrual = 0,
          EopDate = "2022-02-28T00:00:00",
          EopBasHoldingValueAtMarketPrice = 7159142.25,
          EopBasInterestAccrual = 0,
          AccPeriodBasTwrAtExposureValue = -0.107066381156318,
          AccPeriodLocTwrAtExposureValue = -0.107066381156318,
          AccBasIrr = 0,
          AccLocIrr = 0,
          AccBasMwr = -0.107181136120043,
          PeriodBasIrr = 0,
          PeriodLocIrr = 0,
          PeriodBasTwrAtMarketPrice = -0.107066381156318,
          PeriodLocTwrAtMarketPrice = -0.107066381156318,
          PeriodBasTwrDeposit = 0,
          PeriodBasTwrWithdrawal = 0,
          PeriodBasTwrDepositWithdrawal = 0,
          PeriodBasTwrDividendTax = 0,
          PeriodBasTwr = -7673.25,
          PeriodBasMwr = -0.0535618639528656,
          BenchmarkCalcType = "BenchmarkNotCalculated",
          EopBenchmarkName = "",
          AccBasBenchmarkReturnPct = 0,
          PeriodBasBenchmarkReturnPct = 0
        ),
        class = "data.frame",
        row.names = 1L
      )
    )
  ),
  class = "data.frame",
  row.names = c(NA,
                3L)
)

所以在数据中.在上面的框架中，我唯一感兴趣的列是"Id"和"EopBasHoldingValueAtMarketPrice"，后者是嵌套数据中的一列.框架名为"Sumperion".我试图通过以下方式实现这一目标:

df_subset = subset(df, select = c("Id", "SumPeriod$EopBasHoldingValueAtMarketPrice"))

但我得到了一个错误:

frame`(x, r, vars, drop = drop) : undefined columns selected

你们知道如何做到这一点吗？