How to Clear a Filter - AngularJS

I'm very new to AngularJS and was playing with filters today. I was able to apply the filter filter to display only rows matching the criteria from the select menus. However, I was unable to add a "clear filter" function to the button. How can I reset the filter when the button is clicked?

In the following Plunker, you can see the code I was using in attempts achieve this: Plunker - AngularJS Sample

You can use ng-click to bind click handler to clear query variable within a scope.

http://plnkr.co/edit/p1DnoV

The ng-click directive can be used to set the filter model to any falsey-but-not-false Javascript value, such as '', undefined, null or {}.

In the following code, clicking on the div would reset the customFilter model.

<input type="text" ng-model="customFilter" />
<div ng-click="customFilter = undefined">
    Clear Filter
</div>

Here's a link to an updated fork of your Plunker project using Angular v1.4.1