Finding ngOption selected within ngRepeat

I have a table which is populated with directive ngRepeat, and within each item is ngOptions. On change I call function transactionListFilter in the controller to find out which select has changed, so I can then reset all other select to default value 'Multiple'.

View

<tr data-ng-repeat="item in $ctrl.tableData">
    <td>
        <select 
         data-ng-options="item.appAndType for item in item.serviceUIs" 
         data-ng-model="selectedItem" 
         data-ng-change="$ctrl.transactionListFilter(selectedItem)" >
         <option value="">Multiple</option>
        </select>
    </td>                                    
</tr>

Controller

function transactionListFilter(data) {
    console.log(data)
    $scope.filter = data;
};      

So it should look like this:

But if I select the second select, the first select stll is populated with an application number, rather than resetting to 'Multiple'. When I submit ngModel value, it submits the data form the ngOptions.

Question

How do I identify the selected select from the controller, so I can reset all other select value to 'Multiple'?

One approach is to make the selection a property of the ng-repeat iterator:

<tr data-ng-repeat="item in $ctrl.tableData">
    <td>
        <select data-ng-options="ui.appAndType for ui in item.serviceUIs" 
                data-ng-model="item.selectedUi" 
                data-ng-change="$ctrl.transactionListFilter(item,$index)" >
           <option value="">Multiple</option>
        </select>
    </td>                                    
</tr>

function transactionListFilter(item, index) {
    $ctrl.tableData.forEach( (_ , idx) => {
         if (index != idx) {
             _.selectedUi = null;
         };
    });  
    console.log(item.selectedUi, index)
};