仅做记录，未整理格式
css部分未完全，每个筛选条件为固定宽度

实现效果

单行筛选条件时不触发更多按钮，且做占位处理
多行筛选条件时默认收起


同时设定最大/最小宽度并监听该组件宽度变化

filter.vue组件
<template>
  <div :class="`new-filter-block ${!showMoreFilter?'new-filter-block_hidden':''}`">
    <div id="resize-element" ref="filter" class="new-filter-slotBox" >
      <slot />
      <div v-show="seizeList.length"  v-for="(item, index) in seizeList" :key="index"  class="new-filter-item_seize"/>
    </div>
    <div class="new-filter-btnBox">
      <el-button class="new-second-btn" @click="search" >搜索</el-button>
      <el-button @click="reset" >重置</el-button>
      <div :class="`new-filter-more ${!moreFilter?'new-filter-more_hidden':''}`" @click="handleMoreFilter" >
        {{ showMoreFilter ? '收起' : '更多' }} <i class="el-icon-arrow-down" />
      </div>
    </div>
  </div>
</template>

<script>
export default {
  name: 'LFilters',
  emits: ['search', 'reset'],
  props: {
  },
  data() {
    return {
      showMoreFilter: false,
      moreFilter: false,
      observer: null,
      oldWidth: 0,// 记录下旧的数据，避免重复触发回调函数
      seizeList:[],//空白占位数据
      filterCount:0,//筛选条件的个数，保证不受占位符的影响
    }
  },
  mounted() {
    this.filterCount=this.$refs.filter.children.length
    const resizeObserver = new ResizeObserver(entries => {
    // 回调
      const curBoxWidth = entries[0].contentBoxSize[0].inlineSize
      this.handleFilterResize(curBoxWidth)
    })

    // 监听筛选条件盒子
    resizeObserver.observe(this.$refs.filter)
  },
  methods: {
    /**
     * 高级筛选
     */
    handleMoreFilter() {
      this.showMoreFilter = !this.showMoreFilter
    },
    // 触发搜索事件
    search() {
      this.$emit('search')
    },
    reset() {
      this.$emit('reset')
    },
    // 处理筛选条件宽度变化
    handleFilterResize(boxW) {
      if (!boxW || this.oldWidth === boxW) return
      this.oldWidth = boxW
      const itemMinW = 280
      const marginR = 10
      const filterItemW = itemMinW + marginR
      const rowCount = Math.floor(boxW / filterItemW)
      const filterCount = this.filterCount
      this.moreFilter = filterCount > rowCount
      if(this.moreFilter){//设置占位列表长度，最多为rowCount
        let excessiveCount=filterCount%rowCount
        this.seizeList=new Array(rowCount-excessiveCount).fill('')
      }
    }
  }
}
</script>

<style lang="scss" scoped>
@import '@/styles/variables.scss';
::v-deep{
  .el-input__inner,
  .el-date-editor,
  .el-range-separator,
  .el-input__icon {
    height: 32px !important;
    line-height: 32px !important;
  }
  .el-select, .el-cascader, .el-input  {
    width: 100%;
    min-width: 140px;
    .el-input__inner{
      padding-right: 12px !important;
    }
  }
  .el-cascader__tags {
    // display: none;
    .el-tag{
      display: none;
    }
  }
  .el-date-editor {
    width: 100%;
    .el-range-separator {
      width: 16px;
      padding: 0;
    }
  }
}
.new-filter-block{
  padding: 12px;
  background-color: #F8F8F8;
  display: flex;
  // flex-wrap: wrap;
  .new-filter-slotBox{
    flex: 1;
    display: flex;
    flex-wrap: wrap;
    .new-filter-item_seize,
    .new-filter-item{
      flex: 1;
      min-width: 280px;
      max-width: 340px;
      margin-bottom: 10px;
      display: flex;
      flex-wrap: nowrap;
      align-items: center;
      font-size: 14px;
      color: $text-col-3;
      margin-right: 10px;
    }
    .new-filter-itemLabel {
      width: 88px;
      text-align: right;
      margin-right: 12px;
      word-break: keep-all;
    }
  }
  .new-filter-btnBox{
    display: flex;
    font-size: 12px !important;
    .el-button {
      width: 54px;
      height: 32px;
      padding: 0;

    }
    .new-filter-more{
      width: 54px;
      height: 32px;
      line-height: 32px;
      margin-left: 10px;
      color:$blue;
      cursor: pointer;
    }
    .new-filter-more_hidden{
      visibility: hidden;
    }
  }
}
.new-filter-block_hidden{
  height: 56px;
  overflow: hidden;
}

</style>

使用
 <LFilters @search="()=>search()" @reset="()=>emptyQuery()" >
 	//...等宽筛选条件
 </LFilters>