el-tree的数据是用内部实现的一个node-store存储的，没有直接对外提供过滤后的数据，但是可以通过refs拿到带visible属性的所有节点数据：this.$refs.tree.store.root.childNodes

通过两个递归方法，可以从这个childNodes中提取出想要的数据。如下图：

完整代码demo地址：demo

<script src="//unpkg.com/vue@2/dist/vue.js"></script>
<script src="//unpkg.com/element-ui@2.15.8/lib/index.js"></script>
<div id="app">
  <el-input placeholder="输入关键字进行过滤" v-model="filterText"> </el-input>

  <el-tree
    class="filter-tree"
    :data="data"
    :props="defaultProps"
    default-expand-all
    :filter-node-method="filterNode"
    ref="tree"
  >
  </el-tree>
  <el-row>
    <el-button type="primary" @click="setCurrentData">获取当前node数据</el-button>
  </el-row>
  <el-row>
    <div>{{current}}</div>
  </el-row>
</div>

var Main = {
    watch: {
      filterText(val) {
        this.$refs.tree.filter(val);
      }
    },

    methods: {
      filterNode(value, data) {
        if (!value) return true;
        return data.label.indexOf(value) !== -1;
      },
      filterItem(value, data) {
        if (!value) return true;
        return data.text.indexOf(value) !== -1;
      },
      // 获取过滤后的数据的操作代码
      setCurrentData() {
        const traverseNode = function(node) {
          if (Object.prototype.toString.call(node) === '[object Array]') {
            return node.map(t => traverseNode(t))
          }
          const data = {id: node.id, label: node.label, visible: node.visible, children: []}
          const childNodes = node.childNodes;
          childNodes.forEach((child) => {
            const item = traverseNode(child)
            if (item.visible) {
              data.visible = true
            }
            data.children.push(item)
          });
          return data
        };
        const traverseVisible = function(arr) {
          return arr.filter(t => {
            let visible = t.visible
            if (!visible) {
              return false
            }
            if (t.children) {
              t.children = traverseVisible(t.children)
            }
            delete t.visible
            return visible
          })
        }
        const data = traverseNode(this.$refs.tree.store.root.childNodes)
        this.current = traverseVisible(data)
      }
    },

    data() {
      return {
        filterText: '',
        data: [{
          id: 1,
          label: '一级 1',
          children: [{
            id: 4,
            label: '二级 1-1',
            children: [{
              id: 9,
              label: '三级 1-1-1'
            }, {
              id: 10,
              label: '三级 1-1-2'
            }]
          }]
        }, {
          id: 2,
          label: '一级 2',
          children: [{
            id: 5,
            label: '二级 2-1'
          }, {
            id: 6,
            label: '二级 2-2'
          }]
        }, {
          id: 3,
          label: '一级 3',
          children: [{
            id: 7,
            label: '二级 3-1'
          }, {
            id: 8,
            label: '二级 3-2'
          }]
        }],
        defaultProps: {
          children: 'children',
          label: 'label'
        },
        current: {},
      };
    }
  };
var Ctor = Vue.extend(Main)
new Ctor().$mount('#app')

原文地址：el-tree 实现过滤之后，如何得到过滤后的数据？