ui/file_manager/file_manager/foreground/js/ui/breadcrumb.html

<style>
  :host([hidden]),
  [hidden] {
    display: none !important;
  }

  :host-context(html.col-resize) > * {
    cursor: unset !important;
  }

  :host {
    align-items: center;
    display: flex;
    font-family: 'Roboto Medium';
    font-size: 14px;
    outline: none;
    overflow: hidden;
    user-select: none;
    white-space: nowrap;
  }

  span[caret] {
    -webkit-mask-image: url(../../images/files/ui/arrow_right.svg);
    -webkit-mask-position: center;
    -webkit-mask-repeat: no-repeat;
    background-color: currentColor;
    display: inline-flex;
    height: 20px;
    min-width: 20px;
    padding: 8px 0;
    width: 20px;
  }

  :host-context(html[dir='rtl']) span[caret] {
    transform: scaleX(-1);
  }

  button {
    /* don't use browser's background-color. */
    background-color: unset;
    border: 1px solid transparent;
    border-radius: 4px;
    color: var(--google-grey-700);
    cursor: pointer;
    display: inline-block;

    /* don't use browser's button font. */
    font: inherit;
    height: 32px;
    margin: 0;

    /* elide wide text */
    max-width: 200px;
    /* text rendering debounce: fix a minimum width. */
    min-width: calc(12px + 1em);
    outline: none;
    overflow: hidden;
    padding: 0 8px;

    /* text rendering debounce: center. */
    text-align: center;
    text-overflow: ellipsis;
  }

  button[disabled] {
    color: var(--google-grey-900);
    cursor: default;
    font-weight: 500;
    margin-inline-end: 4px;
  }

  span[elider] {
    --tap-target-shift: -7px;
    -webkit-mask-image: url(../../images/files/ui/menu_ng.svg);
    -webkit-mask-position: center;
    -webkit-mask-repeat: no-repeat;
    background-color: currentColor;
    height: 48px;
    margin-inline-start: var(--tap-target-shift);
    margin-top: var(--tap-target-shift);
    min-width: 48px;
    position: relative;
    transform: rotate(90deg);
    width: 48px;
  }

  button[elider] {
    border-radius: 50%;
    box-sizing: border-box;
    display: inline-flex;
    height: 36px;
    min-width: 36px;
    padding: 0;
    width: 36px;
  }

  button.dropdown-item {
    position: relative;
  }

  :host-context(:root.pointer-active) button.dropdown-item:active {
    background-color: rgba(0, 0, 0, 4%);
  }

  :host-context(:root:not(.pointer-active)) button.dropdown-item > paper-ripple {
    display: none;
  }

  button.dropdown-item > paper-ripple {
    --paper-ripple-opacity: 8%;
    color: black;
  }

  button:not([disabled]):not(:active):hover {
    background-color: rgba(0, 0, 0, 4%);
  }

  :host-context(:root.pointer-active) button:not(:active):hover {
    background-color: unset;
    cursor: default;
  }

  :host-context(:root.focus-outline-visible) > button:focus {
    background-color: unset;
    border: 1px solid var(--google-blue-600);
  }

  :host([checked]) button[elider] {
    background-color: rgba(0, 0, 0, 12%);
  }

  button:active {
    background-color: rgba(0, 0, 0, 12%);
  }

  #elider-menu button {
    border: unset;
    color: rgb(51, 51, 51);
    display: block;
    font-family: 'Roboto';
    font-size: 13px;
    max-width: min(288px, 40vw);
    min-width: 192px;  /* menu width */
    padding: 0 16px;
    text-align: start;
  }

  :host-context(:root.focus-outline-visible) #elider-menu button:hover {
    background-color: unset;
  }

  :host-context(:root.focus-outline-visible) #elider-menu button:focus {
    background-color: rgba(0, 0, 0, 4%);
  }
</style>

<button id='first'></button>
<span caret hidden></span>
<button elider aria-haspopup='menu' aria-expanded='false'
    aria-label='$i18n{LOCATION_BREADCRUMB_ELIDER_BUTTON_LABEL}'>
  <span elider></span>
</button>
<span caret hidden></span>
<button id='second'></button>
<span caret hidden></span>
<button id='third'></button>
<span caret hidden></span>
<button id='fourth'></button>
<cr-action-menu id='elider-menu'></cr-action-menu>