BaseViewModel.cs

    public class BaseViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        protected virtual bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = "")
        {
            if (EqualityComparer<T>.Default.Equals(storage, value))
                return false;
            storage = value;
            this.OnPropertyChanged(propertyName);
            return true;
        }
    }

DataStorage.cs

public static class DataStorage
    {
        private static readonly Technical_BestBeforeDates_Model[] data =
            new Technical_BestBeforeDates_Model[]
        {
            new Technical_BestBeforeDates_Model(0, "12", "desc1"),
            new Technical_BestBeforeDates_Model(1, "12", "desc2"),
            new Technical_BestBeforeDates_Model(2, "13", "desc3"),
            new Technical_BestBeforeDates_Model(3, "14", "desc2"),
        };

        private static bool Filter
            (Technical_BestBeforeDates_Model tbm, string code, string description) =>
                (string.IsNullOrEmpty(code) || tbm.ProductCode == code)
            && (string.IsNullOrEmpty(description) || tbm.ProductDescription.Contains(description));

        public static IEnumerable<Technical_BestBeforeDates_Model> GetFilteredData
            (string code, string description) =>
            data.Where(tbm => Filter(tbm, code, description));
    }

RelayCommand.cs

    public class RelayCommand : ICommand
    {
        private Action<object> execute;
        private Func<object, bool> canExecute;

        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }

        public RelayCommand(Action<object> execute, Func<object, bool> canExecute = null)
        {
            this.execute = execute;
            this.canExecute = canExecute;
        }

        public bool CanExecute(object parameter)
        {
            return this.canExecute == null || this.canExecute(parameter);
        }

        public void Execute(object parameter)
        {
            this.execute(parameter);
        }
    }

Technical_BestBeforeDates_Model.cs

    public class Technical_BestBeforeDates_Model
    {
        public Technical_BestBeforeDates_Model(int id, string productCode, string productDescription)
        {
            Id = id;
            ProductCode = productCode;
            ProductDescription = productDescription;
        }

        public int Id { get; private set; }
        public string ProductCode { get; private set; }
        public string ProductDescription { get; private set; }
    }

Technical_BestBeforeDates_Record_ViewModel.cs

    public class Technical_BestBeforeDates_Record_ViewModel : BaseViewModel
    {
        private string productCode;
        private string productDescription;

        public string ProductCode
        {
            get => productCode;
            set => SetProperty(ref productCode, value);
        }

        public string ProductDescription
        {
            get => productDescription;
            set => SetProperty(ref productDescription, value);
        }

        public ObservableCollection<Technical_BestBeforeDates_Model> VMs { get; }

        public Technical_BestBeforeDates_Record_ViewModel()
        {
            VMs = new ObservableCollection<Technical_BestBeforeDates_Model>();
            FilterCommand = new RelayCommand(_ => UpdateDataFromDatabase());

            UpdateDataFromDatabase();
        }

        public void UpdateDataFromDatabase()
        {
            VMs.Clear();
            // dummies, replace with call to a DB
            var records = DataStorage.GetFilteredData(ProductCode, ProductDescription);
            foreach (Technical_BestBeforeDates_Model model in records)
            {
                VMs.Add(model);
            }
        }

        public ICommand FilterCommand { get; }
    }

ui.xaml

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <TextBlock
            Grid.Row="0"
            Grid.Column="0"
            Margin="5"
            HorizontalAlignment="Center"
            Text="Code" />
        <TextBlock
            Grid.Row="1"
            Grid.Column="0"
            Margin="5"
            HorizontalAlignment="Center"
            Text="Description" />
        <TextBox
            Grid.Row="0"
            Grid.Column="1"
            Margin="5"
            Text="{Binding ProductCode}" />
        <TextBox
            Grid.Row="1"
            Grid.Column="1"
            Margin="5"
            Text="{Binding ProductDescription}" />
        <Button
            Grid.Row="2"
            Grid.Column="1"
            MaxWidth="100"
            Margin="5"
            HorizontalAlignment="Right"
            Command="{Binding FilterCommand}"
            Content="Filter" />
    </Grid>
    <DataGrid
        Grid.Row="1"
        AutoGenerateColumns="False"
        ColumnWidth="auto"
        IsReadOnly="True"
        ItemsSource="{Binding VMs}">
        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding Id}" Header="Id" />
            <DataGridTextColumn Binding="{Binding ProductCode}" Header="Product Code" />
            <DataGridTextColumn Binding="{Binding ProductDescription}" Header="Product Description" />
        </DataGrid.Columns>
    </DataGrid>
</Grid>