const menuWrapper = document.querySelector('.portfolio-menu'),
          menuElems = menuWrapper.querySelectorAll('li'),
          allButton = menuWrapper.querySelector('.all'),
          loveButton = menuWrapper.querySelector('.lovers'),
          chefButton = menuWrapper.querySelector('.chef'),
          girlButton = menuWrapper.querySelector('.girl'),
          guyButton = menuWrapper.querySelector('.guy'),
          grandmotherButton = menuWrapper.querySelector('.grandmother'),
          grandfatherButton = menuWrapper.querySelector('.granddad');  const buttons = {};
'all,love,chef,girl,boy,grandma,grandpa'
  .split(',').forEach((name) => buttons[name] = menuWrapper.querySelector('.' + name));Использовать потом, например, вместо girlButton — buttons.girl      
  
  const menuQuerySelector = (selectors) => selectors.map((s) => menuWrapper.querySelector(s));
  
  const buttonSelectors = ['.b1', '.b2', '.b3', '.b4', ...];
  const [button1, button2, button3, button4, ...] = menuQuerySelector(buttonSelectors);      
  
  let objects = {
        allButton: {
            wrapper: 'menuWrapper',
            selector: 'li',
            'function': 'querySelectorAll'
        },
        loveButton : {
            wrapper: 'menuWrapper',
            selector: '.lovers',
            'function': 'querySelector'
        },
    };
    Object.entries(objects).forEach(entry => {
        const [key, value] = entry;
        const wrapper = document.querySelector(value.wrapper);
        value.object = wrapper[value.function](value.selector);
    });      
  
  const menuWrapper = document.querySelector(".portfolio-menu");
if (menuWrapper !== null) {
  const [all, lovers, chef, girl, guy, grandmother, granddad] = [
    ".all",
    ".lovers",
    ".chef",
    ".girl",
    ".guy",
    ".grandmother",
    ".granddad",
  ].map((selector) => {
    return menuWrapper.querySelector(selector);
  });
  const menuElems = menuWrapper.querySelectorAll("li");
}