How to expand sub dropdown menu snippets/content box upper?

Question

As I go deeper in the submenu each following box comes closest down to the page and the bottom part of the content box is not seen. I want to justify the following boxes vertically center by the screen. how can I shift the openning boxes upper. Find below the my codes.

.dropdown-submenu-left > .dropdown-menu {
  left: auto;
  right: 100%;
}

/* For space-saving menus */
.dropdown-submenu > .dropdown-menu.dropdown-menu-compact {
  left: 50%;
  top: 100%;
}
.dropdown-submenu-left > .dropdown-menu.dropdown-menu-compact {
  left: auto;
  right: 50%;
}

.dropdown-submenu-left > a:after {
  visibility: hidden;
}
.dropdown-submenu-left > a:before {
  display: block;
  font: normal normal normal 14px/1 FontAwesome;
  font-size: inherit;
  text-rendering: auto;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transform: translate(0, 0);
  display: block;
  content: "\f0d9";
  float: left;
  color: #333333;
  margin-top: 2px;
  margin-left: -10px;
}



a[data-snippet-code]:after {
    content: attr(data-snippet-code); /* Read from the data-snippet-code attribute */
    font-family: monospace;
    font-size: 100%;
    position: absolute;
    width: auto;
    display: table;
    left: 50%;
    white-space: pre;
    z-index: 10000;
    background: #E8E8E8;
    padding: 4px;
    border-color : #AAA;
    border-style: solid;
    border-width: 1px;
    visibility: hidden;
    vertical-align: middle;
}
a[data-snippet-code]:hover:after {
    visibility: visible;
    transition: all 0s ease 1s;
}

I tried the solve this problem by changing the options of each attribue but didn't work.