模板使用（lay-module/searchSelect），依赖于 jquery、layui.dist 中的 dropdown 模块实现（所以data 格式请参照 layui文档）

<link rel="stylesheet" href="layui-v2.5.6/dist/css/layui.css" />
<link rel="stylesheet" href="lay-module/searchSelect/index.css" />

<form id="app-form" class="layui-form layuimini-form">
	<div class="layui-form-item">
      <label class="layui-form-label">测试</label>
      <div class="layui-input-block search-select-component">
        <!-- data-init以title字段作为显示 -->
        <input name="tags" data-init='[{"id":1,"title":"123"}]' placeholder="Search..." class="layui-input search-select-input" />
      </div>
    </div>
    <div class="layui-form-item">
      <button type="submit" class="layui-btn" lay-submit lay-filter="demo-submit">确认</button>
      <button type="reset" class="layui-btn">重置</button>
    </div>
</form>

<script src="jquery.min.js"></script>
<script src="layui-v2.5.6/dist/layui.js"></script>
<script src="lay-module/searchSelect/index.js"></script>
<script>
layui.use(['jquery','form'], function () {
    const $ = layui.jquery;
    const form = layui.form;
    
    // 搜索下拉选择组件处理方法（默认拾取元素 elem: '.search-select-input'）
	layui.searchSelect.render({
      onSearch: function (search) {
        console.log('onSearch', search);
        $.ajax({
          url: '/api/gelist',
          type: 'GET',
          data: {
            key: search.name,
            val: search.value,
          },
          dataType: 'json',
          success: function (res) {
            if (res.code == 1) {
              // res.data 中的 "title字段" 作为显示名称
              search.update(res.data);
            } else {
              layer.msg(res.msg, { icon: 2 });
            }
          },
          error: function () {
            layer.msg('network error', { icon: 2 });
          },
        });
      },
    });

	// 表单提交处理
	form.on('submit(demo-submit)', function(data){
		// 使用 layui.searchSelect.getValue 获取所有 searchSelect 值，传入 name 可以只取对应的value
		// 对应的value也会设置到对应的 .search-select-input 的 data-val 中
		const dd = layui.searchSelect.getValue();
		console.log(data, dd)
	});
});
</script>

searchSelect 模块实现（lay-module/searchSelect 目录中添加以下 index.js、index.css 文件）

1、index.css

.search-select-component .tags.select-list {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 10px;
  margin-bottom: 20px;
  border: none;
}

.search-select-component .tags.select-list:empty {
  margin-top: 0;
  margin-bottom: 0;
}

.search-select-component .select-list-item {
  position: relative;
  padding-right: 20px;
  padding-top: 2px;
}

.search-select-component .select-list-item .name {
  font-size: 14px;
}

.search-select-component .select-list-item .del {
  position: absolute;
  top: 0;
  right: 0;
  font-size: 30px;
  font-weight: normal;
  line-height: 20px;
  float: none;
  width: 18px;
  padding: 0;
  cursor: pointer;
  text-align: center;
  opacity: 1;
  color: #ea0000;
  border: 0 none;
  background: transparent none repeat scroll 0 0;
  text-shadow: none;
}

.search-select-component .layui-layer-msg {
  top: 40% !important;
}

2、index.js 文件

/*
 * @Author: mojon
 * @Date:   2025-02-19 11:40:42
 * @Last Modified by:   hi916
 * @Last Modified time: 2025-02-19 15:52:33
 * @Last Modified description: 搜索下拉选择组件（多选）
 */
layui.define(['jquery', 'dropdown'], function (exports) {
  'use strict';
  const $ = layui.jquery;
  const dropdown = layui.dropdown;

  // 绑定值
  let values = {};

  // 删除item
  function delItem(event) {
    const name = $(event.target).data('name');
    const value = $(event.target).data('value');
    console.log('删除item', name, value);

    if (values[name]) {
      values[name] = values[name].filter((item) => JSON.stringify(item) != JSON.stringify(value));
      $(event.target).parent().remove();
      $(event.target).data('val', values[name]);
    }
  }

  // 添加item
  function addItem(el, value) {
    const name = $(el).attr('name');
    values[name].push(value);
    $(el).data('val', values[name]);

    console.log('添加item', name, values[name]);

    // item容器
    const div = document.createElement('div');
    div.classList.add('select-list-item');

    // title显示 (以title字段作为显示)
    const span = document.createElement('span');
    span.classList.add('name');
    span.textContent = value.title;

    // del按钮
    const btn = document.createElement('button');
    btn.classList.add('del');
    btn.textContent = 'x';
    btn.setAttribute('type', 'button');
    btn.setAttribute('data-name', name);
    btn.setAttribute('data-value', JSON.stringify(value));
    // 监听删除事件
    btn.addEventListener('click', delItem);

    div.appendChild(span);
    div.appendChild(btn);

    $(el).siblings('.tags.select-list').append(div);

    // $(el).siblings('.tags.select-list').append(`
    //     <div class="select-list-item">
    //       <span class="name">${data.title}</span>
    //       <button type="button" class="del">×</button>
    //     </div>
    // `);
  }

  // 监听选择
  function onSelect(el) {
    // 插入选择存放位置
    $(el).after('<div class="tags select-list"></div>');
    // 获取配置
    const name = $(el).attr('name');
    const width = $(el).width();
    const dropdown = layui.dropdown;
    const dropdownHeight = 300;
    dropdown.render({
      elem: el,
      id: name,
      position: 'absolute', // 设置位置为相对
      data: [],
      style: `
          max-height: ${dropdownHeight}px;
          width: ${width}px;
          overflow-y: auto;
          overflow-x: hidden;
      `,
      click: function (obj) {
        if (values[name]) {
          const isInclude = values[name].find((item) => JSON.stringify(item) == JSON.stringify(obj));
          // 没有重复选择
          if (!isInclude) addItem(el, obj);
        }
      },
    });
  }

  // 更新下拉选择列表
  function updateDropdown(name, data) {
    dropdown.reload(name, { data, show: true });
  }

  // 监听执行搜索
  function onSearch(el, callback = () => {}) {
    let timer = null;
    $(el).on('input', function (e) {
      const val = $(this).val();
      const data = $(this).data();
      const name = $(el).attr('name');
      clearTimeout(timer);
      timer = setTimeout(() => {
        if (val) {
          console.log('搜索onSearch', val);
          callback({
            ...data,
            name: name,
            value: val,
            update: (data) => updateDropdown(name, data),
          });
        }
      }, 500);
    });
  }

  // 初始化（处理初始状态显示）
  function init(el) {
    const name = $(el).attr('name');
    const initValues = $(el).data('init');
    if (initValues) {
      initValues.forEach((value) => addItem(el, value));
    }
    console.log('初始化init', name, values);
  }

  // 获取值
  function getValue(name) {
    if (name) {
      return values[name];
    } else {
      return values;
    }
  }

  // 加载配置
  function render(options) {
    // 配置
    const opt = {
      elem: '.search-select-input',
      onSearch: () => {},
      ...options,
    };

    // 遍历所有 searchSelect
    $(opt.elem).each((index, el) => {
      const name = $(el).attr('name');
      if (name) {
        // 生成预处理值
        values[name] = [];
        // 监听选择
        onSelect(el);
        // 监听搜索
        onSearch(el, opt.onSearch);
        // 初始化处理
        init(el);
      }
    });
  }

  // 组件初始化
  function Component() {
    return {
      render: render,
      getValue: getValue,
    };
  }

  exports('searchSelect', new Component());
});