How can I create a Nested List with a search bar, which should be
located under the title. For instance, on the fourth Sencha Nested
List example, how would I insert a Search Bar (code below) so that it
looks like this image:

Example Search Bar:
Ext.define('Sencha.view.SearchBar', {
extend: 'Ext.Toolbar',
xtype : 'searchbar',
requires: ['Ext.field.Text', 'Ext.field.Search'],
config: {
ui: 'searchbar',
layout: 'vbox',
items: [
{
xtype: 'title',
title: 'Search'
},
{
xtype: 'searchfield',
placeHolder: 'Search...'
}
]
}
});
You’ll need to add it after the Nested List has been instantiated, so the docking position is correct.