Accessing value outside of for loop (ion-slides + button)

I have the following problem. I have a for loop which shows a list of users and i have a button (outside of the loop) which needs to perform an action on the current user on list. How is it possible to save the value of each key to a variable each time the user swipes left or right?

Here is my code (I have used some buttons inside the slides to show what i need to do with the buttons which are outside)

<ion-slides #mainSlider (ionSlideDidChange)="slideChanged()">
      <template ngFor let-user [ngForOf]="users | async">
        <template [ngIf]="user.$key !== uid">
              <ion-row *ngIf="premium">
                <ion-col (click)="like(user.$key)">
                  <button ion-button icon-left clear small>
                     <ion-icon name="add-circle"></ion-icon>
        <ion-col width-25 class="img-center" (click)="like()">
          <img src="assets/images/Premium-slide5-A.png" />

I can get the current index of each slide but that won’t do. I have also tried to use NgModel to assign the value from each ion-slide to a variable but again not successfully…

Any help?