How to split a string to multiple arrays based on multiple separators in javascript

I have seen the questions but none of them helped me.
I have a string like this:

var Lang_Array1 = "HU,blah,blah,blah,EN,blah,blah,blah,blah,DE,blah,blah,blah,RO,blah,blah,blah";

I want that string to be in different arrays based on the separators "HU", "EN", "DE", "RO".

My approach currently is this(Working but not too elegant):

var Lang_Array1 = Lang_Array.split(",");
	console.log(typeof(Lang_Array));
	console.log(Lang_Array);

	var HU_Langs = [];
	var EN_Langs = [];
	var DE_Langs = [];
	var RO_Langs = [];
	
	for(var i = 0; i < Lang_Array1.length;i++){
		if(Lang_Array1[i] != "EN"){
			if(Lang_Array1[i] != ""){
				HU_Langs[i] = Lang_Array1[i];
			}
		}else{
			for(i;i < Lang_Array1.length;i++){
				if(Lang_Array1[i] != "DE"){
					if(Lang_Array1[i] != ""){
						EN_Langs[i] = Lang_Array1[i];
					}
				}else{
					for(i;i < Lang_Array1.length;i++){
						if(Lang_Array1[i] != "RO"){
							if(Lang_Array1[i] != ""){
								DE_Langs[i] = Lang_Array1[i];
							}
						}else{
							for(i;i < Lang_Array1.length;i++){
									if(Lang_Array1[i] != ""){
										RO_Langs[i] = Lang_Array1[i];
									}		
								}
							break;
						}
					}
					break;
				}
			}
			break;
		}
	}

That way i get what i want but i want to improve it somehow.
The arrays:

HU_Langs =["HU","blah","blah","blah"];
EN_Langs =["EN","blah","blah","blah"];
DE_Langs =["DE","blah","blah","blah"];

etc...

So how can i improve this code without nested for loops?

EDIT: Thank you for all! All the answers are very very good.
My question wasnt clear and detailed enough but i solved it like this with the help of the correct answer.

Here is the function now:

function Get_Language_Object(Lang_Array){
	Lang_Array = Lang_Array.replace(/(\r\n|\n|\r)/gm, "");
	var langs = ['HU', 'EN', 'DE', 'RO'];
	var isLang = str => langs.includes(str);
	var { HU: New_HU_Langs, EN: New_EN_Langs, DE: New_DE_Langs, RO: New_RO_Langs } = Lang_Array.split(',')
  		.reduce((r, str) => {
    if(isLang(str)) r.push([]);
    	r[r.length - 1].push(str);
    	return r;
  	}, [])
  		.reduce((r, [code, ...arr]) => ({ ...r, [code]: arr }), {});
	for(var i = 0; i < TAGS.length;i++){
		arrLang.HU[TAGS[i]] = New_HU_Langs[i];
		arrLang.EN[TAGS[i]] = New_EN_Langs[i];
		arrLang.DE[TAGS[i]] = New_DE_Langs[i];
		arrLang.RO[TAGS[i]] = New_RO_Langs[i];
	}
	Set_Actual_Language();
	VNotify("Settings Notfy","Lang Set!","success",1500,"success32.png");
}

Split the string by the delimiter (,), reduce the array, and for every language code, add a new sub-array. Push all items to the last sub-array:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

var Lang_Array1 = "HU,blah,blah,blah,EN,blah,blah,blah,blah,DE,blah,blah,blah,RO,blah,blah,blah";

var langs = ['HU', 'EN', 'DE', 'RO'];

var isLang = str => langs.includes(str);

var result = Lang_Array1.split(',')
  .reduce((r, str) => {
    if(isLang(str)) r.push([]);
    
    r[r.length - 1].push(str);
  
    return r;
  }, []);
  
console.log(result);

<!-- end snippet -->

If you want to split to multiple arrays, reduce the sub-arrays to an object, and use desturcturing to assign them to variables:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

var Lang_Array1 = "HU,blah,blah,blah,EN,blah,blah,blah,blah,DE,blah,blah,blah,RO,blah,blah,blah";

var langs = ['HU', 'EN', 'DE', 'RO'];

var isLang = str => langs.includes(str);

var { HU: HU_Langs, EN: EN_Langs, DE: DE_langs, RO: RO_langs } = Lang_Array1.split(',')
  .reduce((r, str) => {
    if(isLang(str)) r.push([]);
    
    r[r.length - 1].push(str);
  
    return r;
  }, [])
  .reduce((r, [code, ...arr]) => ({ ...r, [code]: arr }), {});
  
console.log(HU_Langs, EN_Langs, DE_langs, RO_langs);

<!-- end snippet -->

You should reduce the list of words after splitting on your delimiter (,). Each time you run into a known key, you alter the key that refers to the current language.

This is the most succinct example:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

let arr = "HU,blaf,blaf,blaf,EN,blah,blah,blah,blah,DE,bla,bla,bla,RO,bah,bah,bah"
let keys = [ "DE", "EN", "HU", "RO" ]
let dict = langDict(arr, keys)

console.log(dict)

function langDict(arr, keys) {
  let key = null
  return arr.split(/,/g).reduce((dict, token) => {
    if (Object.keys(dict).length && key == null) {
      throw new Error('No language defined yet!')
    } else if (keys.includes(token)) {
      key = token
    } else {
      if (dict[key] == null) dict[key] = []
      dict[key].push(token)
    }
    return dict
  }, {})
}

<!-- language: lang-css -->

.as-console-wrapper { top: 0; max-height: 100% !important; }

<!-- end snippet -->

As I believe the upper case ISO2 code is the language hint, you could group all results together in a more scalable way.

var Lang_Array1 = "HU,blah,blah,blah,EN,blah,blah,blah,blah,DE,blah,blah,blah,RO,blah,blah,blah";
var Languages = {};
var current = '';

Lang_Array1.split(',').forEach(function (value) {
  if (/^[A-Z]{2}$/.test(value))
    current = value;
  else
    Languages[current] = (Languages[current] || []).concat(value);
});

console.log(Languages);

Above snippet would populate the Languages object like this:

{
  "HU": [
    "blah",
    "blah",
    "blah"
  ],
  "EN": [
    "blah",
    "blah",
    "blah",
    "blah"
  ],
  "DE": [
    "blah",
    "blah",
    "blah"
  ],
  "RO": [
    "blah",
    "blah",
    "blah"
  ]
}

At this point, all you have to do is to address directly Languages.EN or others, or recreate the original structure via:

var Lang_Array = Object.keys(Languages).reduce(
  function (arr, key) {
    return arr.concat(key, Languages[key]);
  },
  []
);

You could also create arrays with the language starting at index 0, and values following:

var Lang_EN = ['EN'].concat(Languages.EN);

As summary, grouping by keys seem the best way to represent, and manipulate, such flattened structure.

I hope this helped 👋

If the order is constant:

var Lang_Array1 = "HU,blah1,blah2,blah3,EN,blah4,blah5,blah6,blah7,DE,blah8,blah9,blah10,RO,blah11,blah12,blah13";
const arr1 = Lang_Array1.split(/[HU,EN,DE,RO]/g);
let obj = {hu:[],en:[],de:[],ro:[]};
const keys = Object.keys(obj);
let i = 0;
arr1.forEach(el=>{
	if(el !== '')
	  obj[ keys[i] ].push(el);
  else
    if(obj[ keys[i] ].length > 0)
      i++;
 });

console.log(obj);

Response:

{hu: Array(3), en: Array(4), de: Array(3), ro: Array(3)}
hu: (3) ["blah1", "blah2", "blah3"]
en: (4) ["blah4", "blah5", "blah6", "blah7"]
de: (3) ["blah8", "blah9", "blah10"]
ro: (3) ["blah11", "blah12", "blah13"]

Temporary array can be used to reference the array to push to :

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

var Lang_Array = "HU,blah,blah,blah,EN,blah,blah,blah,blah,DE,blah,blah,blah,RO,blah,blah,blah";
var Lang_Array1 = Lang_Array.split(","), HU_Langs = [], EN_Langs = [], DE_Langs = [], RO_Langs = [];

for (var Langs = [], i = 0; i < Lang_Array1.length; i++)
{
  var str = Lang_Array1[i];

  Langs = { HU: HU_Langs, EN: EN_Langs, DE: DE_Langs, RO: RO_Langs }[str] || Langs;

  Langs.push(str);
}

console.log( HU_Langs, EN_Langs, DE_Langs, RO_Langs );

<!-- end snippet -->