Multi Auto Complete is a TextView Field user-interface which is used to get multiple strings from the user. XML file:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
    android:id="@+id/layout">

    <MultiAutoCompleteTextView
        android:id="@+id/multiAutoCompleteTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginStart="47dp"
        android:layout_marginTop="136dp"
        android:text="MultiAutoCompleteTextView" />
</RelativeLayout>

This Example is developed and tested in Android Studio 3.1.4 API level 26 Java File:

package com.example.android.sampleproject; 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter; 
import android.widget.MultiAutoCompleteTextView;

public class MainActivity extends AppCompatActivity {
    MultiAutoCompleteTextView multi;
    ArrayAdapter<String> adapter;
    String[] array={"Pulkit","Ramesh sir","Gaurav","Ankit"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main); 
        adapter=new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,array);
       
        multi=findViewById(R.id.multiAutoCompleteTextView);
        multi.setAdapter(adapter);
        multi.setThreshold(1);
        multi.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());

        }
}

MultiAutoComplete Example:

MultiAutoComplete TextView