dspace-angular/themes/mantis/app/shared/search-form/search-form.component.html

<form #form="ngForm" (ngSubmit)="onSubmit(form.value)" class="row" action="/search">
    <div *ngIf="isNotEmpty(scopes)" class="col-12 col-sm-3">
        <select [(ngModel)]="scope" name="scope" class="form-control" aria-label="Search scope"
                (change)="onScopeChange($event.target.value)">
            <option value>{{'search.form.search_dspace' | translate}}</option>
            <option *ngFor="let scopeOption of scopes"
                    [value]="scopeOption.id">{{scopeOption?.name ? scopeOption.name : 'search.form.search_dspace' | translate}}</option>
        </select>
    </div>
    <div [ngClass]="{'col-sm-9': isNotEmpty(scopes)}" class="col-12">
        <div class="form-group input-group"
             [ngClass]="{'input-group-lg': large}">
            <input type="text" [(ngModel)]="query" name="query" class="form-control"
                   aria-label="Search input">
            <span class="input-group-append">
            <button type="submit"
                    class="search-button btn btn-{{brandColor}}">{{ ('search.form.search' | translate) }}</button>
        </span>
        </div>
    </div>
</form>