你不需要额外的<mask>。
由于瓶子的形状，您可以使用圆形<rect>作为clip-path：

waterLevel.addEventListener('input', e => {
  let value = +e.currentTarget.value
  tubeLiquid.setAttribute('stroke-dasharray', `${value} 100`)
})

svg {
  width: 20%;
}

<h3>Draw clip-path</h3>
<svg viewBox="0 0 300 300">
    <image width="300" href="https://i.ibb.co/Mhfwtxp/image-removebg-preview-1.png" />
    <!-- test clip path -->
    <rect x="115" y="55" width="69" height="235" rx="20" ry="20" fill="red" />
  </svg>

<h3>Draw liquid fill</h3>
<svg viewBox="0 0 300 300">
    <image width="300" href="https://i.ibb.co/Mhfwtxp/image-removebg-preview-1.png" />
    <line x1="149.5" y1="290" x2="149.5" y2="50" stroke="green" stroke-width="70" />
  </svg>

<h3>Apply clip path</h3>
<p><input type="range" min="0" max="100" value="100" id="waterLevel" name="water-level" /></p>
<svg viewBox="0 0 300 300">
    <clipPath id="clip">
          <rect x="115" y="55" width="69" height="235" rx="20" ry="20" fill="red" />
    </clipPath>
    <image width="300" href="https://i.ibb.co/Mhfwtxp/image-removebg-preview-1.png" />
    <line id="tubeLiquid" clip-path="url(#clip)" pathLength="100" stroke-dasharray="100 100" x1="149.5" y1="290" x2="149.5" y2="50" stroke="#74ccf4" stroke-width="80" />
  </svg>

首先绘制裁剪路径和填充比例/进度条形状-不裁剪任何东西-找到正确的坐标和尺寸。
然后你可以应用clip-path。
我使用了一个<line>元素作为“tubeLiquid”元素，因为它允许我们将pathLength属性设置为100。
我们可以通过更新stroke-dasharray属性来轻松更改当前的填充值：

// show 100 %
stroke-dasharray="100 100"

// show 50 %
stroke-dasharray="50 100"

在SO上，您会发现很多例子都使用这种方法来制作各种动态 Jmeter /进度条或动画饼图，如"Set svg progress bar percentage in javascript"

我找到的最接近的解决方案是，我没有装满整个瓶子，但你只需要改变多边形中的一些坐标，我没有关于形状和多边形的知识。

<style>
.item {
  width: 150px;
  height: 150px;
}

#tubeLiquid {
  background-color: #74ccf4;
  clip-path: polygon(45% 19%, 41% 22%, 41% 29%, 41% 36%, 41% 43%, 41% 50%, 41% 57%, 41% 63%, 41% 70%, 41% 77%, 41% 83%, 41% 90%, 43% 93%, 50% 92%, 56% 93%, 60% 88%, 59% 81%, 60% 75%, 60% 68%, 60% 61%, 59% 55%, 59% 48%, 59% 42%, 59% 35%, 59% 29%, 58% 23%, 54% 19%);
}

#bottleMask{
  background-color: #FFFFFF;
  clip-path: polygon(45% 19%, 41% 22%, 41% 29%, 41% 36%, 41% 43%, 41% 50%, 41% 57%, 41% 63%, 41% 70%, 41% 77%, 41% 83%, 41% 90%, 43% 93%, 50% 92%, 56% 93%, 60% 88%, 59% 81%, 60% 75%, 60% 68%, 60% 61%, 59% 55%, 59% 48%, 59% 42%, 59% 35%, 59% 29%, 58% 23%, 54% 19%);
}</style>

<div class="item">
  <svg viewBox="0 0 300 300">
    <defs>
      <mask id="bottleMask" fill="white">
        <path d="M0,0h300v300H0V0z M89,68h122v147H89V68z" />
      </mask>
      <clipPath id="liquidClip">
        <path d="M89,68h122v147H89V68z" />
      </clipPath>
    </defs>
    <image width="300" xlink:href="https://i.ibb.co/Mhfwtxp/image-removebg-preview-1.png" />
    <path id="tubeLiquid" fill="#74ccf4" d="M0,0h300v300H0V0z" clip-path="url(#liquidClip)" mask="url(#bottleMask)" />
  </svg>
</div>