source: https://www.simplifiedcoding.net/create-options-menu-recyclerview-item-tutorial/

adapter.java

package net.simplifiedcoding.recyclerviewoptionsmenu;

import android.content.Context;
import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.widget.PopupMenu;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.List;

/**
 * Created by Belal on 29/09/16.
 */

public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {

    private List<MyList> list;
    private Context mCtx;

    public CustomAdapter(List<MyList> list, Context mCtx) {
        this.list = list;
        this.mCtx = mCtx;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.list_items, parent, false);
        return new ViewHolder(v);
    }

    @Override
    public void onBindViewHolder(final CustomAdapter.ViewHolder holder, int position) {
        MyList myList = list.get(position);
        holder.textViewHead.setText(myList.getHead());
        holder.textViewDesc.setText(myList.getDesc());

        holder.buttonViewOption.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                //creating a popup menu
                PopupMenu popup = new PopupMenu(mCtx, holder.buttonViewOption);
                //inflating menu from xml resource
                popup.inflate(R.menu.options_menu);
                //adding click listener
                popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                    @Override
                    public boolean onMenuItemClick(MenuItem item) {
                        switch (item.getItemId()) {
                            case R.id.menu1:
                                //handle menu1 click
                                break;
                            case R.id.menu2:
                                //handle menu2 click
                                break;
                            case R.id.menu3:
                                //handle menu3 click
                                break;
                        }
                        return false;
                    }
                });
                //displaying the popup
                popup.show();

            }
        });
    }


    @Override
    public int getItemCount() {
        return list.size();
    }


    public class ViewHolder extends RecyclerView.ViewHolder {

        public TextView textViewHead;
        public TextView textViewDesc;
        public TextView buttonViewOption;

        public ViewHolder(View itemView) {
            super(itemView);

            textViewHead = (TextView) itemView.findViewById(R.id.textViewHead);
            textViewDesc = (TextView) itemView.findViewById(R.id.textViewDesc);
            buttonViewOption = (TextView) itemView.findViewById(R.id.textViewOptions);
        }
    }
}

list_items.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        android:elevation="4dp">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="@dimen/activity_horizontal_margin">

            <TextView
                android:id="@+id/textViewHead"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Your Heading"
                android:textAppearance="?android:textAppearanceLarge" />

            <TextView
                android:id="@+id/textViewDesc"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/textViewHead"
                android:text="Lorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi molestie nisi dui. "
                android:textAppearance="?android:textAppearanceMedium" />

            <TextView
                android:id="@+id/textViewOptions"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentRight="true"
                android:layout_alignParentTop="true"
                android:paddingLeft="@dimen/activity_horizontal_margin"
                android:text="&#8942;"
                android:textAppearance="?android:textAppearanceLarge" />


        </RelativeLayout>

    </android.support.v7.widget.CardView>

</LinearLayout>

options_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
 
    <item
        android:id="@+id/menu1"
        android:title="Menu 1" />
 
    <item
        android:id="@+id/menu2"
        android:title="Menu 2" />
 
    <item
        android:id="@+id/menu3"
        android:title="Menu 3" />
 
 
</menu>