Пробовал, включая p-fieldset внутри p-dataview.Работает как положено.может быть проблема с условием * ngIf.
Компонент:
cars = [{
id: 1,
items: [{
name: 'car1',
description: 'this is car1 description'
},{
name: 'car2',
description: 'this is car2 description'
},{
name: 'car3',
description: 'this is car3 description'
},{
name: 'car4',
description: 'this is car4 description'
},{
name: 'car5',
description: 'this is car5 description'
}]
}];
Шаблон:
<p-dataView [value]="cars" [paginator]="true" [rows]="5">
<p-header>List of Cars</p-header>
<p-footer>Choose from the list.</p-footer>
<ng-template let-car pTemplate="listItem">
<p-fieldset legend="Header" *ngIf="car.id === 1" [toggleable]="true">
<div *ngFor="let _car of car.items">
{{_car.name}} - {{_car.description}}
</div>
</p-fieldset>
</ng-template>
</p-dataView>
См. Прикрепленный скриншот.