How to convert mysql query result into multidimensional array in laravel with query builder

Make use of the laravel relationships :

$response = Products::with(['productDetails',
                'productDetails.productAttributes',
                'productDetails.productAttributes.subImage'])->get();

If you want the response as array :

$response = $response->toArray();

Products Model

In the products model add the hasMany relationship, in the screenshot the product details is mentioned as an array, if you have multiple entries for the product details table use the hasMany or else use hasOne relationship

/**
 * If you have multiple details in product details table
 */
public function productDetails(){
    return $this->hasMany(ProductsModel::class,'product_id','id');
}

has one relationship

/**
 * If you have single entry for product details table
 */
public function productDetails(){
    return $this->hasOne(ProductsModel::class,'product_id','id');
}

ProductDetails Model

Inside the product details model add the relationship to the product attributes table

public function productAttributes(){
    return $this->hasMany(ProductAtrributesModel::class,'product_detail_id','id');
}

ProductAtrributesModel Model

Inside the product attributes model add the relationship with the images to the product attributes table

public function subImages(){
    return $this->hasMany(ProductSubImagesModel::class,'product_attribute_id','id');
}