获取一组唯一的父项。对于每个唯一的父项，查找所有子项，获取所有费用（即财产名称以单词“expense”开头的地方），提取所有费用值，并检查是否存在正数和负数的混合。然后，如果父项满足该测试，则提取该父项的所有条目并将其包括在结果中。

const data = [{"parent":"A","child":"RST","expense1":1,"expense2":2,"expense3":3},{"parent":"A","child":"EST","expense1":4,"expense2":5,"expense3":6},{"parent":"A","child":"QST","expense1":4,"expense2":2,"expense3":6},{"parent":"B","child":"EST","expense1":1,"expense2":2,"expense3":-3},{"parent":"B","child":"VST","expense1":6,"expense2":2,"expense3":3},{"parent":"B","child":"NST","expense1":3,"expense2":8,"expense3":7},{"parent":"C","child":"UST","expense1":-8,"expense2":-2,"expense3":3},{"parent":"C","child":"PST","expense1":-6,"expense2":-5,"expense3":-3},{"parent":"C","child":"LST","expense1":-3,"expense2":-8,"expense3":-7},{"parent":"D","child":"WST","expense1":-8,"expense2":-2,"expense3":-3},{"parent":"D","child":"CST","expense1":-6,"expense2":-5,"expense3":-3},{"parent":"B","child":"KST","expense1":-3,"expense2":-8,"expense3":-7}]

console.log([...new Set(data.map(i=>i.parent))]
  .filter(parent=>data.filter(i=>i.parent===parent)
  .flatMap(i=>Object.entries(i).filter(([k])=>k.startsWith('expense'))
  .map(([k,v])=>Math.abs(v)===v))
  .reduce((a,c,i,r)=>a || i>0 && c!==r[i-1],false))
  .flatMap(parent=>data.filter(i=>i.parent===parent)))

当你不了解高阶函数（https://eloquentjavascript.net/05_higher_order.html）的时候，过滤数组可能会有点棘手，基本上它们抽象了我们可以使用if循环和elses来删除或添加我们想要的代码。
我不太明白你的问题，因为我做的输出和你想要的不一样，但我坚持排除所有只有正面或只有负面的东西。
幸运的是，这不是一个问题，因为您可以在函数中我为此注解掉的部分实现自己的逻辑。
基本上我们所做的就是使用数组的原生函数，过滤并为它的每一行添加一个逻辑，如果满足这个逻辑，则将该行返回到我想要的最终数组。
完整代码：

// Input
let input = [
  { 'parent': 'A', 'child': 'RST', 'expense1': 1, 'expense2': 2, 'expense3': 3 },
  { 'parent': 'A', 'child': 'EST', 'expense1': 4 4, 'expense2': 5, 'expense3': 6 },
  { 'parent': 'A', 'child': 'QST', 'expense1': 4, 'expense2': 2, 'expense3': 6 },
  { 'parent': 'B', 'child': 'EST', 'expense1': 1, 'expense2': 2, 'expense3': -3 }
  { 'parent': 'B', 'child': 'VST', 'expense1': 6, 'expense2': 2, 'expense3': 3 },
  { 'parent': 'B', 'child': 'NST', 'expense1': 3, 'expense2': 8, 'expense3': 7 },
  { 'parent': 'C', 'child': 'UST', 'expense1': -8, 'expense2': -2, 'expense3': 3 },
  { 'parent': 'C', 'child': 'PST', 'expense1': -6, 'expense2': -5, 'expense3': -3 }
  { 'parent': 'C', 'child': 'LST', 'expense1': -3, 'expense2': -8, 'expense3': -7 }
  { 'parent': 'D', 'child': 'WST', 'expense1': -8, 'expense2': -2, 'expense3': -3 }
  { 'parent': 'D', 'child': 'CST', 'expense1': -6, 'expense2': -5, 'expense3': -3 }
  { 'parent': 'B', 'child': 'KST', 'expense1': -3, 'expense2': -8, 'expense3': -7 }
]

// Output
let output = [
  { 'parent': 'B', 'child': 'EST', 'expense1': 1, 'expense2': 2, 'expense3': -3 }
  { 'parent': 'B', 'child': 'VST', 'expense1': 6, 'expense2': 2, 'expense3': 3 },
  { 'parent': 'B', 'child': 'NST', 'expense1': 3, 'expense2': 8, 'expense3': 7 },
  { 'parent': 'C', 'child': 'UST', 'expense1': -8, 'expense2': -2, 'expense3': 3 },
  { 'parent': 'C', 'child': 'PST', 'expense1': -6, 'expense2': -5, 'expense3': -3 }
  { 'parent': 'C', 'child': 'LST', 'expense1': -3, 'expense2': -8, 'expense3': -7 },
]

const filterLogic = rowOfInput => {
  if ( // Add logic to include or exclude line
    (rowOfInput.expense1 < 0 && rowOfInput.expense2 < 0 && rowOfInput.expense3 < 0) ||
    (rowOfInput.expense1 > 0 && rowOfInput.expense2 > 0 && rowOfInput.expense3 > 0)
  ) return rowOfInput // if is your desired, return that line
}

let inputFiltered = input.filter(filterLogic)

console.log(output)
console.log(inputFiltered)

用www.DeepL.com/Translator翻译（免费版）