JSFiddle - React, Tailwind, and code Playground
HTML
<script src="https://code.jquery.com/jquery-3.4.1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.4.1/semantic.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.4.1/semantic.min.css">
<div style="padding:10px;width:200px;">
<select id="du_select" class="ui fluid dropdown" name="du_graph_types" multiple="">
<option value="">Select DU</option>
<option value="all">All</option>
<option value="copper">Copper</option>
<option value="fiber">Fiber</option>
<option value="common">Common</option>
</select>
</div>
JavaScript
$('#du_select').dropdown({
action: function(text, value) {
// nothing built in occurs
existing_elems = $(this).dropdown("get value")
//console.log(value)
if (existing_elems.includes('all')) {
alert('No options allowed to add, while "All" is already selected')
} else if (existing_elems.length > 0 && value == 'all') {
alert('Before selecting "All", clear the existing DU type')
} else {
$(this).dropdown('set selected',value)
}
$(this).dropdown('hide')
}
});