Tableau api 人构成的画面或场景。如何访问计算字段中其他记录的字段值？

在Tableau中，我需要创建新的计算字段。 此字段应该是其他记录字段的总和，请参见屏幕截图

我正在努力做到以下几点：

IF [Town1] = "Mullingar.Co..." AND [Trip Type1] = "Holiday Trips"

THEN
    IF [Town1] = "Mullingar.Co..."
       AND [Trip Type1] = "Holiday Trips"
       AND [Region1] = 2
    THEN [Trip Count1] END
    +
    IF [Town1] = "Mullingar.Co..."
       AND [Trip Type1] = "Holiday Trips"
       AND [Region1] = 3
    THEN [Trip Count1] END
    +
    IF [Town1] = "Mullingar.Co..."
       AND [Trip Type1] = "Holiday Trips"
       AND [Region1] = 4
    THEN [Trip Count1] END
END

---

但它总是返回NULL。

您可能希望使用FIXED尝试LOD表达式。类似于 {固定[Town1]：和[Trip Count1]}