前端大佬们，这段代码如何优化？

    const getSelectedChildFacets = function (parent) {
              parent?.childrens?.forEach((child) => {
                  if (child.selected && !child.partiallySelected) {
                      // 如果是全选
                      if (parentValues.includes(child.value)) {
                          // 如果是父节点，非子节点则继续向下查找
                          getSelectedChildFacets(child);
                      } else {
                          // 如果是子节点，则存起来
                          arrSelectedFacets.push(child.value);
                      }
                  } else if (child.selected && child.partiallySelected) {
                      // 如果是半选，则继续向下查找
                      getSelectedChildFacets(child);
                  }
              });
          };

        arrFacetValues.forEach((parent) => {
            if (parent.selected && !parent.partiallySelected) {
                // 全选
                if (parentValues.includes(parent.value)) {
                    // 全选且是父节点，向下查找
                    getSelectedChildFacets(parent);
                } else {
                    // 子节点则存到树组中
                    arrSelectedFacets.push(parent.value);
                }
            }
            if (parent.selected && parent.partiallySelected) {
                // 如果是半选，继续向下查找
                getSelectedChildFacets(parent);
            }
        });

如何将两个方法合并成一个方法如图parentValues = ['BC', 'BC-SRV', 'BC-SRV-COM'],想得到的是选中的树组arrSelectedFacets = ['BC-SRV-COM-FTP', 'BC-SRV-COM-TEL']

const arrFacetValues = [
                {
                  value: "BC",
                  selected: true,
                  partiallySelected: true,
                  childrens: [
                    {
                      value: "BC-SRV",
                      selected: true,
                      partiallySelected: true,
                      childrens: [
                        {
                          value: "BC-SRV-COM",
                          selected: true,
                          partiallySelected: true,
                          childrens: [
                            {
                              value: "BC-SRV-COM-FTP",
                              selected: true,
                              partiallySelected: false,
                              childrens: [],
                            },
                            {
                              value: "BC-SRV-COM-TEL",
                              selected: true,
                              partiallySelected: false,
                              childrens: [],
                            },
                          ],
                        }
                      ],
                    }
                  ],
                }
              ]

如果 BC-SRV-COM 下的子节点都选中，则arrSelectedFacets=['BC-SRV-COM']