please how to modify the Filament Resource for adding/editing as follows:

i need Unis listing in CheckboxList to be split into columns by Unit->department_id. Currently, all the units are listed together, but for the sake of overview, I want to have many of them in columns so that each column contains only units with the same department_id.
my code :

<?php
namespace AppFilamentResources;

use FilamentForms;
use FilamentResourcesResource;
use AppFilamentResourcesClientResourcePages;
use FilamentTables;
use FilamentTablesTable;
use FilamentFormsComponentsCheckboxList;
use FilamentFormsComponentsFieldset;
use FilamentFormsComponentsGrid;
use AppModelsClient;
use CarbonCarbon;
use AppModelsDepartment;
use AppModelsUnit;

class ClientResource extends Resource
{
    protected static ?string $model = Client::class;

    protected static ?string $navigationIcon = 'heroicon-o-briefcase';

    public static function form(FormsForm $form): FormsForm
    {
        return $form
            ->schema([
                Fieldset::make('Base informations')
                    ->schema([
                        FormsComponentsTextInput::make('client_name')
                            ->required()
                            ->maxLength(255)
                            ->label('Name'),
                        FormsComponentsSelect::make('department_id')
                            ->label('Client zone')
                            ->options(Department::all()->pluck('name', 'id'))
                            ->reactive()
                            ->required(),
                        FormsComponentsDatePicker::make('valid_from')
                            ->required()
                            ->default(now())
                            ->label('Valid From'),
                        FormsComponentsDatePicker::make('valid_to')
                            ->required()
                            ->default(Carbon::now()->addYear())
                            ->label('Valid To'),
                        FormsComponentsToggle::make('enabled')
                            ->label('Enabled')
                            ->default(true)
                            ->inline(false),
                    ])
                    ->columns([
                        'sm' => 2,
                        'md' => 2,
                        'lg' => 3,
                        'xl' => 4,
                        '2xl' => 5,
                    ]),

                Fieldset::make('Units by Department')
                    ->schema([
                        CheckboxList::make('units')
                            ->label('Units')
                            ->options(
                                Unit::all()
                                    ->sortBy('department_id')
                                    ->mapWithKeys(function ($unit) {
                                        return [$unit->id => $unit->name . ' (' . $unit->department->name . ')'];
                                    })
                                    ->toArray()
                            )
                            ->columns(3)
                            ->searchable()
                            ->bulkToggleable(),
                    ])
            ]);
    }

    public static function table(TablesTable $table): TablesTable
    {
        return $table
            ->columns([
                TablesColumnsTextColumn::make('client_name')
                    ->label('Name'),
                TablesColumnsTextColumn::make('department.name')
                    ->label('Client zone'),
                TablesColumnsTextColumn::make('valid_from')
                    ->date()
                    ->label('Valid From'),
                TablesColumnsTextColumn::make('valid_to')
                    ->date()
                    ->label('Valid To'),
                TablesColumnsTagsColumn::make('units.name')
                    ->label('Units'),
                TablesColumnsTextColumn::make('created_at')
                    ->dateTime()
                    ->label('Created At'),
                TablesColumnsTextColumn::make('updated_at')
                    ->dateTime()
                    ->label('Updated At'),
            ])
            ->filters([
                // Možnosti filtrov, ak sú potrebné
            ])
            ->actions([
                TablesActionsEditAction::make(),
                TablesActionsDeleteAction::make(),
            ])
            ->bulkActions([
                TablesActionsBulkActionGroup::make([
                    TablesActionsDeleteBulkAction::make(),
                ]),
            ]);
    }

    public static function getRelations(): array
    {
        return [
            // Definujte vzťahy, ak je to potrebné
        ];
    }

    public static function getPages(): array
    {
        return [
            'index' => PagesListClients::route('/'),
            'create' => PagesCreateClient::route('/create'),
            'edit' => PagesEditClient::route('/{record}/edit'),
        ];
    }
}

Many thanks for your help guys