If you are looking how to create menuItem and make them visible or invisible on certain condition, here is way to create menuItems:-

Step 1:- Create items on menu.xml:-

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:com.demo="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".MainActivity">
  <item android:id="@+id/menu_search"
        android:icon="@drawable/search"
        android:title="Setting"
        com.demo:showAsAction="always"/> 
   <item android:id="@+id/menu_setting"
        android:icon="@drawable/setting"
        android:title="Setting"
        com.selectorsdemo:showAsAction="always"/>
</menu>

Step 2:- Code snippet in your main activity:-

@Override
public boolean onCreateOptionsMenu(Menu menu) 
  {
     Toolbar tb = (Toolbar) findViewById(R.id.toolbar);
      tb.inflateMenu(R.menu.menu_main);
     MenuItem itemSearch = menu.findItem(R.id.menu_search);
     MenuItem itemSetting = menu.findItem(R.id.menu_setting);

     if (count % 2 == 0) 
       {
         itemSetting.setVisible(true);
        }
     else
        {
          itemSetting.setVisible(false);
        }

     tb.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener()
        {
        @Override
        public boolean onMenuItemClick(MenuItem item) 
           {
             return onOptionsItemSelected(item);
           }
         });
      return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.menu_search:
            Toast.makeText(this, "Search selected", Toast.LENGTH_SHORT)
                    .show();
            break;
        case R.id.menu_setting:
            Toast.makeText(this, "Action Settings selected", Toast.LENGTH_SHORT)
                    .show();
            break;

        default:
            break;
    }

    return true;
}

step 3:-apply invalidateOptionsMenu() function after the code where your menu items are changing:-

In this example , the visibility of MenuItem is changing according to value of "count", so on ButtonClick when value of count gets changed then invalidateOptionsMenu() is called;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar tb = (Toolbar) findViewById(R.id.toolbar);
        ImageView homeIcon = (ImageView) tb.findViewById(R.id.toolbar_home);
        homeIcon.setOnClickListener(new View.OnClickListener()
         {
            @Override
            public void onClick(View view) 
             {
               count++;
                invalidateOptionsMenu();
            }
        });
        setSupportActionBar(tb);
     }