The data is not rendering in the mat-menu - html

Question

I been trying to create a navbar with a submenu. The nav bar data is rendered successfully but the submenu is not working, I am very new to this. Please let me know where is the problem.
<mat-nav-list class="navigation relative">
<div *ngFor="let link of navLinks; let i=index" style="padding-bottom: 14px;">
<div class="card">
<mat-list-item appAccordionlinks routerLinkActive="active-link" (click)="onClick(link.name)">
<a mat-button [matMenuTriggerFor]="submenu" *ngIf="link?.submenu?.length > 0" appAccordiontoggle
class="relative main-active">
<mat-icon *ngIf="link.icon">{{link.icon}}</mat-icon>
<img class="menu-img" *ngIf="link.img" [src]="link.img" alt="">
<app-menu-icon *ngIf="link.img" [name]="'employee'"></app-menu-icon>
<span>{{link.name}}</span><span fxFlex></span>
</a>
<a *ngIf="!(link?.submenu?.length > 0)" [routerLink]="link.path" appAccordiontoggle
class="relative main-active" mat-ripple fxLayout="row">
<mat-icon *ngIf="link.icon">{{link.icon}}</mat-icon>
<app-menu-icon *ngIf="link.img" [name]="link.name" [color]="link.color"></app-menu-icon>
<!-- <img class="menu-img" *ngIf="link.img" [src]="link.img" alt=""> this is need to mark as comment -->
<span>{{link.name}}</span>
</a>
</mat-list-item>
</div>
</div>
</mat-nav-list>
<mat-menu #submenu>
<ng-container *ngFor="let sublink of link?.submenu">
<ng-container *ngIf="link?.submenu?.length > 0">
<button mat-menu-item>
<img class="menu-img" *ngIf="sublink.img" [src]="sublink.img">
<span>{{sublink.name}}</span>
</button>
</ng-container>
</ng-container>
</mat-menu>

Answer 1

The mat-menu element is out of the scope of link variable. You need to include it (mat-menu) in the div you are dynamically rendering the links, i.e. within link's scope:
<div *ngFor="let link of navLinks; let i = index"...>
<--! card html -->
<mat-menu #submenu>
<--! submenu child elements... -->
</mat-menu>
</div>