I believe you are trying to acheive something similar to this CodePen. The code almost entirely taken from SVNM's answer to this question
Edits from that answer
- Using an image to make the lines/arrow you describe although SVG may be better if you know how to do it
- Positioning and size of the background image
Example HTML for this
<select name="cars" id="cars">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
CSS
select {
-webkit-appearance: none;
-moz-appearance: none;
background: transparent;
background-image: url("https://paul7dxb.github.io/hosted-assets/SomePNGs/arrow.png");
background-repeat: no-repeat;
background-size: 40px 20px;
background-position-x: 80%;
background-position-y: 50%;
border: 1px solid #dfdfdf;
border-radius: 2px;
margin-right: 2rem;
padding: 1rem;
padding-right: 2rem;
}