I see the filtered data on the screen, but the original data does not appear when I clear the input

**
Here I show _todayShare in the <a> tag as an item in order**

 <span>Share</span>
        <input
          [(ngModel)]="sharedsearchText"
          (keyup)="applyFilter(sharedsearchText)"
          style="width: 50%; margin-top: 1px; margin-bottom: 1px;"
          matInput
          placeholder="Ara..."
        />
      </div>
      <div class="list" slim-scroll [slimScrollOptions]="{ height: 450 }">
        <a
          *ngFor="
            let item of _todayShare | keyvalue : valueAscOrder;
            let i = index
          "
          style="cursor: pointer"
          class="transition"
          (click)="showliveRss(item)"
        >

_todayShare is a map as you understand and I made a copy of it below, but again it didn’t work.

_todayShare: Map<string, any> = new Map<string, any>();


ngOnInit() {
        this._todayShare = new Map<string, any>();
....


applyFilter(value: string) {
    
    const filterValue = value.trim().toLowerCase();
    const filteredMap = new Map<string, any>();
    const _todayShareBackup = new Map<string, any>(this._todayShare)

    _todayShareBackup.forEach((item, key) => {
      if (key.toLowerCase().includes(filterValue) ||
        JSON.stringify(item).toLowerCase().includes(filterValue)) {
        filteredMap.set(key, item);
      }
    });
    this._todayShare = filteredMap
  }

When I clear the input here, I want all of my data to come as follows