A <clip-path> defines a shape which acts as a window, only allowing parts of a <path> to show if they are within the <clip-path> shape and cutting off the rest.

<vector xmlns:android="<http://schemas.android.com/apk/res/android>"
    xmlns:tools="<http://schemas.android.com/tools>"
    android:width="24dp"
    android:height="24dp"
    android:viewportWidth="24.0"
    android:viewportHeight="24.0">
    <clip-path
        android:name="square clip path"
        android:pathData="M6,6 h12 v12 h-12 z"/>
    <path
        android:name="triangle"
        android:fillColor="#FF000000"
        android:pathData="M0,24 l12,-24 l12,24 z"/>

</vector>

In this case the <path> produces a black triangle, but the <clip-path> defines a smaller square shape, only allowing part of the triangle to show through: