<div *ngIf = role === 'null' >
      Navbar home
    </div>
    <div *ngIf = role === '1' >
      Navbar 1
    </div>
      <div *ngIf = role === '2' >
      Navbar 2
    </div>

<div *ngIf="role==='null'">
      Navbar home
</div>
<div *ngIf="role==='1'">
      Navbar 1
</div>
<div *ngIf="role==='2'">
      Navbar 2
</div>