I've discovered that the first part is not correctly working either (I thought it was working). E.g. I have this

 if ($scope.searchTerm.message)
                    {
                        var search = $scope.searchTerm.message;
                        $scope.filteredTransactions = $filter('filter')($scope.filteredTransactions, ({ message: search } || { item: search }));
                    }

but when I type something which is supposed to be found in the item column, it returns an empty array. If I type something which is present in the message, it works.

UPDATE. Got an answer on stackoverflow to apply manual filtering.