分析:

1. 首先我们需要实现上图的效果,然后Element-UI的el-select是没有的,所以需要自己写
2. 我们需要用到el-popover组件,然后使用它的v-model="visible"来实现控制显示
3. 我们在el-popover的slot="reference" 放一个el-select
   • 使用popper-append-to-body="false"不需要插入浮动元素
   • 使用popper-class="hide-popper"定义浮窗class为hide-popper,并设置
     display:none,这样选中了就不会存在el-select的下拉选项
   • el-option 循环下面选择的list里面的元素,这样就可以在el-select展示选中的并存在删除
   • el-select双向绑定的就是自定义选择的数组

• html:

  <template>
  	<div class="arrbox">
  		<!-- 通过visible控制显示还是隐藏 -->
  		<el-popover
  		v-model="visible"
  		placement="bottom-start"
  		width="auto"
  		>
  		<div slot="reference" class="check-select">
  			<!-- popper-append-to-body:不需要插入浮动元素,popper-class:设置类名并隐藏 -->
  			<el-select
  			ref="select"
  			v-model="currentval"
  			:style="{width:`${width}px`,height:`${height}`}"
  			multiple
  			:placeholder="placeholder"
  			:popper-append-to-body="false"
  			popper-class="hide-popper"
  			style="width:100%"
  			@visible-change="visibleChange"
  			@focus="getFocus"
  			> <el-option
  			v-for="item in selectItem"
  			:key="`${item.value}_k`"
  			:label="item.label"
  			:value="item.value"
  			/></el-select>
  		</div>
  		<!-- selectBxClick让select强制选中 -->
  		<div class="selectMain" :style="{'min-width':`${width-20}px`}" @click="selectBxClick">
  			<div class="seachButton">
  			<el-select
  				v-model="seachValue"
  				placeholder=" 请选择筛选"
  				style="width:70%;margin-right:10px;max-width:195px"
  				@visible-change="selectBxClick()"
  			>
  				<el-option
  				v-for="item in seachList"
  				:key="item.value"
  				:value="item.value"
  				:label="item.label"
  				/>
  			</el-select>
  			<div class="btn" @click="seachBtn">搜索</div>
  			</div>
  			 <div class="selectDiv">
                                <div v-for="item in list.filter(n=>n.value=='all')" :key="item.value" class="list" :class="[currentval.indexOf(item.value)!=-1?'selected':'',item.value=='all'?'allCheck':'']" @click="clickItem(item)">{{ item.label }}</div>
  
                                <div class="selectDivAuto">
                                  <div v-for="item in list.filter(n=>n.value!='all')" :key="item.value" class="list" :class="[currentval.indexOf(item.value)!=-1?'selected':'',item.value=='all'?'allCheck':'']" @click="clickItem(item)">{{ item.label }}</div>
                                </div>
  
                              </div>
  		</div>
  		</el-popover>
  	</div>
  	</template>
  

• js:

1. 使用getFocus获取是否聚焦,聚焦了让visible=true,这样就可以显示出自定义的下拉选择项

2. 通过visibleChange实施监听el-select,控制el-popover显示

3. 在点击自定义的下拉选择项时,通过@click="selectBxClick"让el-select一直聚焦,这样箭头就会一直向上

4. 通过 @click="seachBtn"和getList获取列表,具体需要自己去自定义

   // 模拟获取的数据
   	const seachClickList = [{value: '1',label: '测试1',type: '1'},{value: '2',label: '测试2',type: '1'},{value: '3',label: '测试3',type: '1'},{value: '4',label: '测试4',type: '2'},{value: '5',label: '测试5',type: '2'},{value: '6',label: '测试6',type: '2'},{value: '7',label: '测试7',type: '2'}]
   	export default {
   	model: {
   		prop: 'parentArr',
   		event: 'change-parentArr'
   	},
   	props: {
   		parentArr: {
   		type: Array,
   		default() {
   			return []
   		}
   		},
   		// 传入选中的item,主要时防止list里面没有选中的数据
   		parentSelectItem: {
   		type: Array,
   		default() {
   			return []
   		}
   		},
   		width: {
   		type: Number,
   		default: 300
   		},
   		height: {
   		type: Number,
   		default: 30
   		},
   		placeholder: {
   		type: String,
   		default: '请输入'
   		}
   	},
   	data() {
   		return {
   		seachList: [
   			{
   			value: '1',
   			label: '条件一'
   			},
   			{
   			value: '2',
   			label: '条件二'
   			}
   		],
   		visible: false,
   		currentval: [],
   		list: [],
   		selectItem: [],
   		seachValue: '1'
   		}
   	},
   	watch: {
   		seachValue: {
   		handler(value) {
   			this.getList(value)
   		},
   		deep: true,
   		immediate: true
   		},
   		parentArr: {
   		handler(value) {
   			this.currentval = value
   		},
   		deep: true,
   		immediate: true
   		},
   		parentSelectItem: {
   		handler(value) {
   			this.selectItem =  value.map(n => {
                                 if (n.value == 'all') {
                                   n.label = '全部'
                                 }
                                 return n
                               })
   		},
   		deep: true,
   		immediate: true
   		},
   		currentval: {
                           handler(value) {
                                   this.$emit('change-parentArr', value)
                           }
   		}
   	},
   	created() {
   	},
   	methods: {
   		getList(value) {
                           this.list = [{
                                   label: '全部',
                                   value: 'all'
                           }, ...seachClickList.filter(n => n.type == value)]
                           this.getSelectItem()
   		},
   		// 获取选中的item
   		getSelectItem() {
                           const noItemList = this.currentval.map(n => {
                                   if (this.selectItem.findIndex(i => i.value == n) == -1) {
                                   return n
                                   }
                                   return null
                           }).filter(n => n != null)
                           noItemList.forEach(item => {
                                   const index = this.list.findIndex(i => i.value == item)
                                   if (index != -1) {
                                   this.selectItem.push(this.list[index])
                                   }
                           })
   		},
   		getFocus() {
                           this.visible = true
   		},
   		visibleChange(data) {
                           this.visible = data
   		},
   		selectBxClick() {
                           // 避免点击框体时组件消失
                           this.$refs.select.visible = true
   		},
   		// 选择
   		clickItem(item) {
                         const index = this.currentval.indexOf(item.value)
                         if (index == -1) {
                           if (item.value == 'all') {
                             this.currentval = ['all']
                             this.selectItem = [{
                               label: '全部',
                               value: 'all'
                             }]
                           } else {
                             this.currentval.push(item.value)
                             this.selectItem.push(item)
                             const currentvalIndex = this.currentval.indexOf('all')
                             const selectItemIndex = this.selectItem.findIndex(n => n.value == 'all')
                             if (currentvalIndex != -1 && selectItemIndex != -1) {
                               this.selectItem.splice(selectItemIndex, 1)
                               this.currentval.splice(currentvalIndex, 1)
                             }
                           }
                         } else {
                           const itemIndex = this.selectItem.findIndex(n => n.value == item.value)
                           this.selectItem.splice(itemIndex, 1)
                           this.currentval.splice(index, 1)
                         }
                       },
   		// 搜索
   		seachBtn() {
                           this.getList()
   		}
   	}
   	}
   

• css:

  1. selected属性使用了el-select的样式,让样子尽量一致

  .arrbox {
  display: inline-block;
  }
  .check-select{
  ::v-deep.hide-popper{
  	display: none;
  }
  }
  ::v-deep .el-input__suffix{
  i:not(.el-select__caret){
  	display: none;
  }
  }
  .selectMain {
  width: 100%;
  height: 100%;
  .seachButton{
  	width: 100%;
  	align-items: center;
  	display: flex;
  	div.btn{
  	width: 25%;
  	max-width: 70px;
  	max-width: 80px;
  	height: 40px;
  	display: flex;
  	align-items: center;
  	justify-content: center;
  	font-size: 12px;
  	color: #fff;
  	background-color: #409EFF;
  	border-radius: 5px;
  	cursor: pointer;
  	}
  }
  .selectDiv{
          width: 100%;
          max-width: 500px;
          margin-top: 10px;
          padding:  0 10px 0 0;
          .list{
            width: 100%;
            padding: 10px 20px 10px 10px;
            color: #666;
            cursor: pointer;
            position: relative;
            &.selected{
              color: #409EFF;
              &::after{
                position: absolute;
                right: 0px;
                top: 50%;
                transform: translateY(-50%);
                font-family: element-icons;
                content: "\e6da";
                font-size: 12px;
                font-weight: 700;
                -webkit-font-smoothing: antialiased;
              }
            }
          }
          .selectDivAuto{
            width: calc(100% + 15px);
            max-height: 300px;
            overflow-y: auto;
            .list{
              padding: 10px 30px 10px 10px;
              &.selected::after{
                right: 10px;
              }
            }
          }
  
        }
  }
  .allCheck{
  border-bottom: 1px solid rgb(228, 225, 225);
  }
  

• 使用

  <template>
  	<seachSelectInput v-model="from.tag" :parentSelectItem='selectItem' :width="302" placeholder="请选择标签" />
  </template>
  <script>
  import seachSelectInput from ./seachSelectInput'
  export default {
  components: {
  	seachSelectInput
  },
  data(){
  	return{
  		from:{
  			tag:['1']
  		},
  		selectItem:[
  			{
  			value: '1',
  			label: '测试1'
  			}
  		]
  	}
  }
  }