Simple tampermonkey script to let a user hide tracks they don't need to see.

hide-unneeded-tracks.user.js

// ==UserScript==
// @name         Hide Unneeded Tracks
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Hide tracks that you don't need to see
// @author       Marisa Goode
// @match        https://learn.codingdojo.com/dashboard
// @icon         https://www.google.com/s2/favicons?domain=codingdojo.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    window.getHiddenTracks = function() {
        let ids = JSON.parse(localStorage.getItem("hidden-tracks"));
        return Array.isArray(ids) ? ids : [];
    }

    window.setHiddenTrack = function(id) {
        let tracksToHide = getHiddenTracks();
        tracksToHide.push(id);
        localStorage.setItem("hidden-tracks", JSON.stringify(tracksToHide));
    }

    window.hideTrack = function(trackId, e) {
        if(e) {
            e.target.remove();
            setHiddenTrack(trackId);
        }
        let selector = `[data-track-id="${trackId}"]`;
        document.querySelector(selector).style.display = "none";
    }

    window.showAllTracks = function() {
        document.querySelectorAll(".btn-hide").forEach(b => b.remove());
        getHiddenTracks().forEach(trackId =>  {
            let selector = `[data-track-id="${trackId}"]`;
            document.querySelector(selector).style.display = "block";
        });
        localStorage.setItem("hidden-tracks", "[]");
        enableHideTracks();
    }

    window.enableHideTracks = function() {
        getHiddenTracks().forEach(id => hideTrack(id));
        document.querySelectorAll("[data-track-id]").forEach(t => {
            if(t.style.display === "none") {
                return;
            }
            const button = document.createElement("button");
            button.textContent = "[hide]";
            button.style = "border:none;background-color:transparent;" +
                "color:#009cc6;cursor: pointer;";
            button.classList = "btn-hide";
            button.onclick = e => hideTrack(t.dataset.trackId, e);
            t.parentNode.insertBefore(button, t);
        });
    }

    let firstTrack = document.querySelector("[data-track-id]");
    const button = document.createElement("button");
    button.textContent = "[show all]";
    button.style = "border:none;background-color:transparent;" +
        "color:#009cc6;cursor: pointer;display:block;";
    button.onclick = e => showAllTracks();
    firstTrack.parentNode.insertBefore(button, firstTrack);
    enableHideTracks();
})();