AddMySubreddits.user.js

// ==UserScript==
// @name 		 Add Reddit Top Menuitems (My Subreddits )
// @description  adds quickaccess menuitems: My Subreddits
// @grant        none
// @match        http://old.reddit.com/*
// @match        https://old.reddit.com/*
// @match        http://*.old.reddit.com/*
// @match        https://*.old.reddit.com/*
// @version      1.1.2
// @namespace 	 https://github.com/ikeman2003/UserscriptRepo
// @author	     ikeman2003
// @downloadURL  https://raw.githubusercontent.com/ikeman2003/UserscriptRepo/main/Userscripts/Old%20Reddit/AddMySubreddits.user.js
// @updateURL	 https://raw.githubusercontent.com/ikeman2003/UserscriptRepo/main/Userscripts/Old%20Reddit/AddMySubreddits.user.js
// ==/UserScript==
//http or https
var http = window.location.href.search("reddit.com");
var subreddit ="";

// get subreddit from url.
var substart = window.location.href.search("/r/")+3;
if (substart>2) {
	// found subreddit
	subreddit = window.location.href.substring(substart); 
	var subend = subreddit.search("/");
	if (subend >0) {
		subreddit= subreddit.substr(0,subend);
	}
	subreddit= '/r/'+ subreddit;
}
var subredditurl = window.location.href.substring(0,http) + 'reddit.com' + subreddit;
$(".flat-list.sr-bar.hover").append('<li><span class="separator">-</span><a class="choice" href="/subreddits/mine/">My Subreddits</a></li>')