force element to display outside of overflow:hidden

This is probably attempting the impossible, but I would like to display an element outside of an element that is overflow: hidden. I know that makes no sense and things are working as they should, but just wanted to double check to see if there is a way.

Best described with this code:

.outer {
  position: fixed;
  top: 30px;
  left: 50px;
  overflow: hidden;
  height: 30px;
  width: 300px;
  background: red;
}

.inner {
  position: relative;
}

.show-up {
  width: 100px;
  height: 300px;
  background: green;
  position: absolute;
  left: 20px;
  overflow: visible;
}

<div class="outer">
  <div class="inner">
    <div class="show-up">this needs to show up ALL 300 pixels high of it</div>
  </div>
</div>

View on JSFiddle

The overflow:hidden definition will hide anything inside that element that extends beyond its bounds.

Depending on your specific application, you may be able to use a structure like this:

.container {
  position: fixed;
  top: 30px;
  left: 50px;
  height: 30px;
  width: 300px;
  background: red;
}
.outer {
  overflow: hidden;
}
.inner {
  position: absolute;
}
.show-up {
  width: 100px;
  height: 300px;
  background: green;
  position: relative;
  margin-left: 20px;
}

<div class="container">
  <div class="outer">
    <div class="inner"></div>
  </div>
  <div class="show-up">this needs to show up ALL 300 pixels high of it</div>
</div>

View on JSFiddle

Make an additional outer div with position relative and set the absolute position of the div you want to move outside of the overflow hidden div.

.container{
  position:relative;
}
.overflow-hid-div{
  overflow:hidden;
  margin-left:50px;
  width:200px;
  height: 200px;
  background-color:red;
}
.inner{
  width:50px;
  height: 50px;
  background-color:green;
  position: absolute;
  left:25px;
  top:25px;

}

<div class='container'>
    <div class='overflow-hid-div'>
        <div class='inner'>
            sup!
        </div>
    </div>
</div>

https://jsfiddle.net/JerryGoyal/ysgrevoh/1/

I was struggling for ages with this for a tooltip. My containing element is overlay: hidden and add I can't add extra wrapper divs because it causes some weird bug with flexbox and ResizeObserver. As far as I know there is no way for a position: absolute element to escape a parent that is both overlay: hidden and position: relative.

However I discovered that position: fixed elements aren't clipped by overlay: hidden at all, and it's actually easier to use position: fixed in my case. Might be an option for some.

please check the following fiddle I created: http://jsfiddle.net/NUNNf/12/

You should add an external container like such:

<div class="container">
    <div class="outer">
        <div class="inner">
            ...
        </div>
    </div>
    <div class="show-up">this needs to show up ALL 300 pixels high of it</div>
</div>

and then add the elements inside.

Styling:

.outer {
    position: absolute;
    top: 30px;
    left: 50px;
    overflow:hidden;
    height: 30px;
    width: 300px;
    background: red;
}

.container {
    position:relative;
}

.inner {
    position: relative;
}

.show-up{
    width: 100px;
    height: 300px;
    background: green;
    position: absolute;
    left: 20px;
    overflow: visible;
    top: 30px;
}