JSFiddle - React, Tailwind, and code Playground

HTML

<select id="type" onclick="filterMarkers(this.value);">
    <option value="">Wybierz kategorię</option>
    <option value="restaurant">pierwsza</option>
    <option value="bar">druga</option>
 </select>
<ul id="pasekBoczny">
    <li class="list-sidebar" id="restaurant"><a href="javascript:myclick(0)">Jasło</a></li>
    <li class="list-sidebar" id="restaurant"><a href="javascript:myclick(1)">Jaworzno</a></li>
    <li class="list-sidebar" id="bar"><a href="javascript:myclick(2)">Jędrzejów</a></li>
    <li class="list-sidebar" id="restaurant"><a href="javascript:myclick(3)">Solidarności</a></li>
    <li class="list-sidebar" id="bar"><a href="javascript:myclick(4)">Łódź</a></li></ul>

JavaScript

$('#type').change(function(){
    if ($(this).val() == "bar") {
        $("#restaurant").hide();
        $("#bar").show();
    } 
    else if ($(this).val() == "restaurant") {
        $("#bar").hide();
        $("#restaurant").show();
    } 
});