AntV官方案例中有这样子的一个，右侧的图不确定是否可修改，你可以看下官方的文档，有绘制连线区域的代码和右侧放大内容的渲染代码

import { Chart } from '@antv/g2';

const otherRatio = 6.67 / 100; // Other 的占比
const otherOffsetAngle = otherRatio * Math.PI; // other 占的角度的一半
const data = [
  { type: '微博', value: 93.33 },
  { type: '其他', value: 6.67 },
];
const other = [
  { type: '论坛', value: 1.77 },
  { type: '网站', value: 1.44 },
  { type: '微信', value: 1.12 },
  { type: '客户端', value: 1.05 },
  { type: '新闻', value: 0.81 },
  { type: '视频', value: 0.39 },
  { type: '博客', value: 0.37 },
  { type: '报刊', value: 0.17 },
];
const chart = new Chart({
  container: 'container',
  autoFit: true,
  height: 500,
});
chart.legend(false);
chart.tooltip({
  showMarkers: false,
});

const view1 = chart.createView({
  region: {
    start: {
      x: 0,
      y: 0,
    },
    end: {
      x: 0.5,
      y: 1,
    },
  },
});
view1.coordinate('theta', {
  radius: 0.7,
  startAngle: 0 + otherOffsetAngle,
  endAngle: Math.PI * 2 + otherOffsetAngle,
});
view1.data(data);
view1.interaction('element-highlight');
view1
  .interval()
  .adjust('stack')
  .position('value')
  .color('type', ['#38c060', '#2593fc'])
  .label('value', function () {
    return {
      offset: -10,
      content: (obj) => {
        return obj.type + '\n' + obj.value + '%';
      },
    };
  });

const view2 = chart.createView({
  region: {
    start: {
      x: 0.5,
      y: 0.1,
    },
    end: {
      x: 1,
      y: 0.9,
    },
  },
});
view2.axis(false);
view2.data(other);
view2.interaction('element-highlight');
view2
  .interval()
  .adjust('stack')
  .position('value')
  .color('type', ['#063d8a', '#0b53b0', '#1770d6', '#2593fc', '#47abfc', '#6dc1fc', '#94d6fd', '#bbe7fe'])
  .label('value', {
    position: 'right',
    offsetX: 5,
    offsetY: 10,
    content: (obj) => {
      return obj.type + ' ' + obj.value + '%';
    },
  });
chart.render();
drawLinkArea();
chart.on('afterpaint', function () {
  drawLinkArea();
});

/* ---------绘制连接区间-----------*/
function drawLinkArea() {
  const canvas = chart.getCanvas();
  const container = chart.backgroundGroup;
  const view1_coord = view1.getCoordinate();
  const center = view1_coord.getCenter();
  const radius = view1_coord.getRadius();
  const interval_geom = view2.geometries[0];
  const interval_container = interval_geom.container;
  const interval_bbox = interval_container.getBBox();
  const view2_coord = view2.getCoordinate();
  // area points
  const pie_start1 = {
    x: center.x + Math.cos(Math.PI * 2 - otherOffsetAngle) * radius,
    y: center.y + Math.sin(Math.PI * 2 - otherOffsetAngle) * radius,
  };
  const pie_start2 = {
    x: center.x + Math.cos(otherOffsetAngle) * radius,
    y: center.y + Math.sin(otherOffsetAngle) * radius,
  };
  const interval_end1 = {
    x: interval_bbox.minX,
    y: view2_coord.end.y,
  };
  const interval_end2 = {
    x: interval_bbox.minX,
    y: view2_coord.start.y,
  };
  const path = [
    ['M', pie_start1.x, pie_start1.y],
    ['L', pie_start2.x, pie_start2.y],
    ['L', interval_end2.x, interval_end2.y],
    ['L', interval_end1.x, interval_end1.y],
    ['Z'],
  ];
  container.addShape('path', {
    attrs: {
      path,
      fill: '#e9f4fe',
    },
  });
  canvas.draw();
}