reset-search-model

// directive
.directive('resetSearchModel',function () {
	return {
		restrict: 'A',
		require: ['^ngModel','uiSelect'],
		link: function (scope, element, attrs, ctrls) {
			if (attrs.resetSearchModel === "true" || attrs.resetSearchModel === true) {
				scope.$watch(attrs.ngModel,function (newval,oldval,scope) {
					scope.$select.selected = undefined;
				});
			}
		}
	};
})

// sample usage - see: 'reset-search-model="true"'
	 <ui-select ng-model="myModel" theme="bootstrap" on-select="searchselect($item)" reset-search-input="true" reset-search-model="true">
	    <ui-select-match placeholder="Search...">{{$select.selected.name}}</ui-select-match>
	    <ui-select-choices refresh="search({val:$select.search})" refresh-delay="300" repeat="item in results">
	        <div ng-bind="item.name"></div>
	   </ui-select-choices>
		</ui-select>