Validate nested object with dot syntax using class-validator and NestJS

I'm having trouble on validating nested object when I try to update a specific prop of a nested object e.g.:

import { Type } from 'class-transformer';
import { IsOptional, IsString, ValidateNested } from 'class-validator';

class Nested {
  @IsString()
  @IsOptional()
  readonly propA: string;

  @IsString()
  @IsOptional()
  readonly propB: string;
}

export class UpdateDto {
  @IsOptional()
  @Type(() => Nested)
  @ValidateNested()
  readonly nested: Nested;
}

If I try to pass a dotted key like { "nested.propA": "test" } I get the following error

{
    "statusCode": 400,
    "message": [
        "property nested.propA should not exist"
    ],
    "error": "Bad Request"
}

A simplest solution can be adding in the parent object the dotted keys eg:

class Nested {
  @IsString()
  @IsOptional()
  readonly propA: string;

  @IsString()
  @IsOptional()
  readonly propB: string;
}

export class UpdateDto {
  @IsOptional()
  @Type(() => Nested)
  @ValidateNested()
  readonly nested: Nested;

  @IsString()
  @IsOptional()
  readonly 'nested.propA': string;    <==== THIS

  @IsString()
  @IsOptional()
  readonly 'nested.propB': string;    <==== THIS
}

With that approach I can pass both the entire object and a single prop, but it seems really redundant to me.

Any other way to validate using a "dot" syntax? The db is mongo where the dot syntax can be used to updating a specific prop of a nested object.

Thanks.