If you have a Facebook group with a large list of pending member requests, running this will find the people who have existing friends in the group, or mutual friends with you, and programatically click their 'Approve' button.

facebook-group-member-request-quick-add.js

/**
 * If you have a Facebook group with a large list of pending member requests, 
 * running this will find the people who have existing friends in the group, 
 * or mutual friends with you, and programatically click their 'Approve' button. 
 * 
 * Obviously it will only work on items that have been loaded into the DOM already, 
 * so if the list is long keep scrolling until you reach the end of it before running this. 
 * 
 * DOM traversal was accurate at the time of creation, but I'm not responsible for
 * you running this after Facebook refactor their HTML/React templates and banning everyone
 * on the list! :D
 * 
 * Hope it saves you some time! 
 **/
 
var f=document.querySelectorAll('[href*=requesters_friends_in_group],[href*=mutual_friend]');
for (var i = 0; i < f.length; i++) {
  f[i].parentNode.parentNode.parentNode.parentNode.parentNode.querySelectorAll('[ajaxify]')[0].click();
}

//Bookmarklet version
javascript:(function(){var f=document.querySelectorAll('[href*=requesters_friends_in_group],[href*=mutual_friend]');for(var i = 0; i < f.length; i++){f[i].parentNode.parentNode.parentNode.parentNode.parentNode.querySelectorAll('[ajaxify]')[0].click();}})();

//Bookmarklet version with alert for number of additions.
javascript:(function(){var f=document.querySelectorAll('[href*=requesters_friends_in_group],[href*=mutual_friend]');for(var i = 0; i < f.length; i++){f[i].parentNode.parentNode.parentNode.parentNode.parentNode.querySelectorAll('[ajaxify]')[0].click();} alert(f.length + ' people added to the group.');})();




//Let people who seem Irish in...
var links=document.querySelectorAll('#pagelet_requests_queue .profileLink'), irish=[], linkText, addLink;
for(var i=0;i<links.length;i++){
  linkText = links[i].innerHTML.toLowerCase();
  if(linkText.indexOf('ireland') > -1 || linkText.indexOf('dublin') > -1 || linkText.indexOf('galway') > -1){
    irish.push(links[i]);
  }
}
for(var i=0;i<irish.length;i++){
  addLink = irish[i].parentNode.parentNode.parentNode.parentNode.parentNode.parentNode.parentNode.parentNode.querySelectorAll('[ajaxify]')[0];
  if(addLink && addLink.innerHTML.indexOf('approve')) {
    addLink.click();
  }
}
alert(irish.length + ' Irish people added...');

//Bookmarklet
javascript:(function(){
var links=document.querySelectorAll('#pagelet_requests_queue .profileLink'), irish=[], linkText, addLink;
for(var i=0;i<links.length;i++){
  linkText = links[i].innerHTML.toLowerCase();
  if(linkText.indexOf('ireland') > -1 || linkText.indexOf('dublin') > -1 || linkText.indexOf('galway') > -1){
    irish.push(links[i]);
  }
}
for(var i=0;i<irish.length;i++){
  addLink = irish[i].parentNode.parentNode.parentNode.parentNode.parentNode.parentNode.parentNode.parentNode.querySelectorAll('[ajaxify]')[0];
  if(addLink && addLink.innerHTML.indexOf('approve')) {
    addLink.click();
  }
}
alert(irish.length + ' Irish people added...');
})();



//Clicks all visible Block buttons. Use care. I use it with the sort feature and sort by recent joins
javascript:(function(){
var links=document.querySelectorAll('#pagelet_requests_queue [ajaxify]');
for(var i=0;i<links.length;i++){
  if(links && links[i].innerHTML.toLowerCase().indexOf('block')) {links[i].click();}
}
alert(links.length + ' people blocked...');
})();

//Ignore users that joined Facebook recently. They can re-apply again in future as they aren't blocked.
var f=document.querySelectorAll('.uiList.mts._2rct._4kg');
for (var i = 0; i < f.length; i++) {
  if(f[i].innerHTML.indexOf('Joined Facebook less than') !== -1) {
    f[i].parentNode.parentNode.querySelectorAll('[ajaxify]')[1].click();
  }
  console.info('New users ignored');
}

//Bookmarklet version
javascript:(function(){var f=document.querySelectorAll('.uiList.mts._2rct._4kg');for (var i = 0; i < f.length; i++) {if(f[i].innerHTML.indexOf('Joined Facebook less than') !== -1) {f[i].parentNode.parentNode.querySelectorAll('[ajaxify]')[1].click();}console.info('New users ignored');}})();



//Block users that joined Facebook recently. 
var f=document.querySelectorAll('.uiList.mts._2rct._4kg');
for (var i = 0; i < f.length; i++) {
  if(f[i].innerHTML.indexOf('Joined Facebook less than') !== -1) {
    f[i].parentNode.parentNode.querySelectorAll('[ajaxify]')[2].click();
  }
  console.info('New facebook users blocked');
}

//Bookmarklet version
javascript:(function(){var f=document.querySelectorAll('.uiList.mts._2rct._4kg');for (var i = 0; i < f.length; i++) {if(f[i].innerHTML.indexOf('Joined Facebook less than') !== -1) {f[i].parentNode.parentNode.querySelectorAll('[ajaxify]')[2].click();}console.info('New Facebook users blocked');}})();





//Allow users that have Ireland mentioned in their card
var f=document.querySelectorAll('.uiList.mts._2rct._4kg');
for (var i = 0; i < f.length; i++) {
  if(f[i].parentNode.innerHTML.indexOf('Ireland') !== -1) {
    f[i].parentNode.parentNode.querySelectorAll('[ajaxify]')[0].click();
    console.info('Irish users added');
  }
}

//Bookmarklet version
javascript:(function(){var f=document.querySelectorAll('.uiList.mts._2rct._4kg');for (var i = 0; i < f.length; i++) {if(f[i].parentNode.innerHTML.indexOf('Ireland') !== -1) {f[i].parentNode.parentNode.querySelectorAll('[ajaxify]')[0].click();console.info('Irish users added');}}})();

This was a nifty one. Guessing it wont work anymore. But did you ever come up with something with similar filtering?

Sorry @rabimba, I only saw your comment now. Nope, I haven't used this recently and I never needed to use anything similar since, sorry