Add / Change parameter of URL and redirect to the new URL

function setGetParameter(paramName, paramValue)
{
    var url = window.location.href;
    var hash = location.hash;
    url = url.replace(hash, '');
    if (url.indexOf(paramName + "=") >= 0)
    {
        var prefix = url.substring(0, url.indexOf(paramName + "=")); 
        var suffix = url.substring(url.indexOf(paramName + "="));
        suffix = suffix.substring(suffix.indexOf("=") + 1);
        suffix = (suffix.indexOf("&") >= 0) ? suffix.substring(suffix.indexOf("&")) : "";
        url = prefix + paramName + "=" + paramValue + suffix;
    }
    else
    {
    if (url.indexOf("?") < 0)
        url += "?" + paramName + "=" + paramValue;
    else
        url += "&" + paramName + "=" + paramValue;
    }
    window.location.href = url + hash;
}

Call the function above in your onclick event.

All the preivous solution doesn't take in account posibility of the substring in parameter. For example http://xyz?ca=1&a=2 wouldn't select parameter a but ca. Here is function which goes through parameters and checks them.

function setGetParameter(paramName, paramValue)
{
  var url = window.location.href;
  var hash = location.hash;
  url = url.replace(hash, '');
  if (url.indexOf("?") >= 0)
  {
    var params = url.substring(url.indexOf("?") + 1).split("&");
    var paramFound = false;
    params.forEach(function(param, index) {
      var p = param.split("=");
      if (p[0] == paramName) {
        params[index] = paramName + "=" + paramValue;
        paramFound = true;
      } 
    });
    if (!paramFound) params.push(paramName + "=" + paramValue);
    url = url.substring(0, url.indexOf("?")+1) + params.join("&");
  }
  else
    url += "?" + paramName + "=" + paramValue;
  window.location.href = url + hash;
}

Why parse the query string yourself when you can let the browser do it for you?

function changeQS(key, value) {
    let urlParams = new URLSearchParams(location.search.substr(1));
    urlParams.set(key, value);
    location.search = urlParams.toString();
}

I had a similar situation where I wanted to replace a URL query parameter. However, I only had one param, and I could simply replace it:

window.location.search = '?filter=' + my_filter_value

The location.search property allows you to get or set the query portion of a URL.