tempermonkey script to help easy filter aj club event

aj_club_filter.js

// ==UserScript==
// @name         filter event by aj club name
// @namespace    http://tampermonkey.net/
// @version      0.1
// @require http://code.jquery.com/jquery-3.3.1.min.js
// @description  add a club index in the head then you could get by event list by club!
// @author       Matt
// @match        https://www.audax-japan.org/*
// @grant        none
// ==/UserScript==


(function() {
    'use strict';
    function onlyUnique(value, index, self) {
        return self.indexOf(value) === index;
    };
    function onlyShowme(event){
        $("table > tbody > tr").each(function(){
            $(this).show();
            if($(this).find("td:nth-child(3)").text() !== event.target.text)
            {
                $(this).hide();
            }
        });
    };
    var club_list = [];
    var only_unique=[];

    $("table > tbody > tr > td:nth-child(3)").each(function(){
        club_list.push($(this).text());
        only_unique = club_list.filter(onlyUnique).filter(function(e) { return e !== '' }).filter(function(e) { return e !== '主催' });
    });

    for(var i = 0; i < only_unique.length; i++) {

        $("#post-21795 > div").prepend("<a id='"+ only_unique[i] +"' style='padding:3px;cursor: context-menu;'>"+ only_unique[i] +"</a>");
    };
    for(var j = 0; j < only_unique.length; j++) {
        $("#"+ only_unique[j]).click(onlyShowme);
    };
})();