Filament's Table builder allows you to group your table rows by date out of the box, but what if you need to group by "month and year"? I encountered this need while working on a project that required viewing purchases grouped by month-year, and after some trial and error, I've figured it out!

Below is the snippet you need:

<?php

use Filament\Resources\Resource;
use Filament\Tables;
use Filament\Tables\Grouping\Group;
use Filament\Tables\Table;
use Illuminate\Database\Eloquent\Builder;

class ReceiptResource extends Resource
{
    protected static ?string $model = Purchase::class;

    protected static ?string $label = 'Purchases';

    public static function table(Table $table): Table
    {
        return $table
            ->recordTitleAttribute('vendor_name')
            ->columns([
                // Ex: "Friday 23. September 2023"
                Tables\Columns\TextColumn::make('date')->label('Purchase Date')->date('l j. F Y'),
                Tables\Columns\TextColumn::make('vendor_name')->label('Vendor'),
                Tables\Columns\TextColumn::make('total_amount')->label('Total Amount'),
            ])
            ->defaultGroup(
            // Group the rows by Year and Month (2023-09, 2023-11 etc) instead of "date"
                Group::make('date')
                    // Ex: "2023-10-0",
                    // Note:  You need the "-0" at the end, so Carbon can parse the date.
                    ->getKeyFromRecordUsing(
                        fn(Purchase $record): string => $record->date->format('Y-m-0')
                    )

                    // Ex: "September 2023"
                    ->getTitleFromRecordUsing(
                        fn(Purchase $record): string => $record->date->format('F Y')
                    )

                    // Set the default ordering
                    ->orderQueryUsing(
                        fn(Builder $query, string $direction) => $query->orderBy('date', 'desc')
                    )
                    // Hide "date: " in the Group title
                    ->titlePrefixedWithLabel(false),
            );
    }
}