PanelMenu is a hybrid of vertical stacked Accordion and hierarchical Tree components. Each parent menu item has a toggleable panel; with the panel, it shows child menu items in a hierarchical Tree format. A basic panel menu example, which displays the document or file type menu would be as follows:

<p-panelMenu [model]="items" ></p-panelMenu>

The list of menu items needs to be organized within a component class. For example, a root menu item titled Help will have nested items as shown here:

this.items = [
  {
    label: 'Help',
    icon: 'fa-question',
    items: [
           {label: 'Contents'},
           {label: 'Search', icon: 'fa-search',
             items: [{label: 'Text', items: [{label: 'Workspace'}]}, 
             {label: 'File'}]}
    ]
  },
  //more items ...
];

The following screenshot shows a snapshot result of the basic panel menu example:

The initial state of each menu item is controlled through the expanded attribute (that is, expanded="true"), which is available on the MenuItem interface level.