Search results on the current page will be checked, if the domain name matches with a list of URLs. If it matches than they will be highlighted and ordered at the start of the result box

Google prioritize and highlight results.user.js

// ==UserScript==
// @name            Google prioritize and highlight results
// @name:de         Google Priorisierung und Hervorhebung von Ergebnissen
// @namespace       kurotaku.de
// @description     Search results on the current page will be checked if the domain name matches with a list of urls, if it matches than they will be highlighted and ordered at the start of the result box
// @description:de  Die Suchergebnisse auf der aktuellen Seite werden daraufhin überprüft, ob der Domainname mit einer Liste von URLs übereinstimmt; wenn dies der Fall ist, werden sie hervorgehoben und am Anfang der Ergebnisbox angeordnet
// @version         2.4.9
// @author          Kurotaku
// @license         MIT
// @include         https://www.google.*/search?*
// @icon            https://www.google.com/favicon.ico
// @updateURL       https://gist.github.com/Kurotaku-sama/ce96f72ac5bb51c7246b51b3b18a30c7/raw/Google%2520prioritize%2520and%2520highlight%2520results.user.js
// @downloadURL     https://gist.github.com/Kurotaku-sama/ce96f72ac5bb51c7246b51b3b18a30c7/raw/Google%2520prioritize%2520and%2520highlight%2520results.user.js
// @require         https://openuserjs.org/src/libs/sizzle/GM_config.js
// @grant           GM_getValue
// @grant           GM_setValue
// @grant           GM_registerMenuCommand
// ==/UserScript==


let is_kp_wp_tab_overview = false; // If its a split up page

(async function() {
    await init_gm_config(); // Initialize the configuration
    // insert_gm_config_button(); // Add the button to the filter container to open the configuration menu

    if(GM_config.get("script_enabled"))
        start_prioritize(); // Start the main part of the Script
})();


function init_gm_config() {
    GM_registerMenuCommand('Settings', () => {
        GM_config.open();
    });
    let frame = document.createElement('div');
    document.body.appendChild(frame);
    GM_config.init(
        {
            'id': 'configuration',
            'title': 'Google prioritize and highlight results config',
            'fields':
            {
                'script_enabled':
                {
                    'label': 'Enable/Disable the prioritize Script',
                    'type': 'checkbox',
                    'default': true
                },
                'url_terms':
                {
                    'label': 'Domain Terms (each domain must be written in a new line)',
                    'type': 'textarea',
                    'default': ''
                },
                'styles':
                {
                    'label': 'CSS Styles',
                    'type': 'text',
                    'default': 'padding: 20px; border: cyan 2px solid'
                }
            },
            'events': {
                'init': () => {GM_config.set("url_terms", GM_config.get("url_terms").replace(/^\s*$(?:\r\n?|\n)/gm, ""))}, // To prevent blank lines
                'save': () => {location.reload()},
            },
            'frame': frame,
            'css': '#configuration {height:auto !important; width:auto !important; padding:20px !important;max-height: 600px !important;max-width:500px !important;} #configuration .config_header {font-size:17pt; font-weight:bold} .field_label {display: block; text-align:center;margin-bottom:10px;} #configuration .config_var {margin-top:10px;} .config_var :nth-child(2) {width: 300px; margin:auto; display:block ;text-align:center;} #configuration_buttons_holder {text-align: center;} #configuration_field_url_terms {height: 150px; width: 300px; resize: none;}'
        });
}


function start_prioritize() {
    // If its a split up page
    is_kp_wp_tab_overview = document.querySelector("#search #kp-wp-tab-overview") !== null;

    // Get searchbox container
    let searchresultbox = is_kp_wp_tab_overview ? document.querySelector("#search #kp-wp-tab-overview") : document.querySelector("#rso > div:last-of-type");
    if(searchresultbox) {
        // Adjust styles for rearangement of results
        searchresultbox.style.display = "grid";
        searchresultbox.style.gridTemplateColumns = "100%";

        // Get Results
        let results = get_resultlist();
        if(results)
            results.forEach((obj, i) => {
                let result = obj.result;
                let index = obj.index;
                style_result(result, index, (index === 0)); // (obj.index === 0) checks if its the last (first one in array) result that should be styled
            });
    }
}


function prepare_url_terms() {
    let url_terms = GM_config.get("url_terms").split("\n"); // Get urls from config and split them
    url_terms = url_terms.map(function (el) {return el.trim();}); // Trim away the spaces
    url_terms = url_terms.filter((el) => el !== ""); // Remove all empty lines (shouldn't happen anymore, but safe is safe)

    // New reversed url_terms for correct ordering [NOT necessary NECESSARY ANYMORE DUE TO FILTER METHOD]
    return url_terms.reverse();
}


function style_result(result, index, last) {
    result.style.order = -1 - index; // Order according to the index
    result.setAttribute("style", result.getAttribute("style") + GM_config.get("styles"));
    result.style.maxWidth = "100%"; // To prevent breaking out of the screen size
    result.querySelector(".g").style.margin = "unset"; // Remove the margin of the results inside
    result.querySelector(".g").style.width = "unset"; // Remove the fixed width (needed on split up pages)
    result.style.margin = !last ? "unset" : "0 0 30px 0"; // Remove the margin of the results
}


function get_resultlist() {
    // Get URL Terms
    let reversed_url_terms = prepare_url_terms();

    // Get the searchresults
    let searchresults = is_kp_wp_tab_overview ? document.querySelectorAll("#search #kp-wp-tab-overview div.TzHB6b") : document.querySelectorAll("#search div.MjjYud");
    if(searchresults) {
        let matching_results = []; // Array for return


        for(let i = 0; i < searchresults.length; i++) {
            let searchresult = searchresults[i];

            let a_tag = searchresult.querySelector("div.yuRUbf a"); // Get URL element
            if(a_tag) {
                let url = a_tag.href.toLowerCase().split('/'); // Split all parts
                let domain = url[2]; // Get only the domainname

                // Check if result contains a string from the array
                let url_index;
                if(reversed_url_terms.some(function(v, index) {
                    url_index = index; // Asign current array index
                    return domain.indexOf(v) >= 0; // Check if Domain fits into url
                })) {
                    // Insert matching searchresult
                    matching_results.push({result: searchresult, index : url_index});
                }
            }
        }
        return matching_results;
    }
    else return false;
}