How to set FieldError field in a custom jsr 303 validation

Question

I am creating a webservice in spring. I have a Params DTO which is nested in my OtherParentDTO's. Each request may contain only certain fields in the params Dto. If the fields are present then I need to do a validation(basically null check). In the custom validator I ll specify which fields needs to be validated for a particular request. My problem is in the controller the error field is returned as params. Is there any way to change it to params.customerId or parmas.userId.

Update customer req:

{"params":{"customerId" : "b2cab997-df13-4cb0-8f67-4357b019bb96"}, "customer":{}}

Update user req:

{"params":{"userId" : "b2cab997-df13-4cb0-8f67-4357b019bb96"}, "user":{}}

@JsonSerialize(include = Inclusion.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class Params {

    private String customerId;
    private String userId;

    //setter and getter are there
}

public class UpdateCustomerRequestDTO {

    @NotNull
    @IsValid(params = {"customerId"}) 
    protected Params params;
    @NotNull @Valid
    private Customer customer;
}

public class UpdateUserRequestDTO {

    @NotNull
    @IsValid(params = {"userId"}) 
    protected Params params;
    @NotNull @Valid
    private User user;
}

Custom constrain validator

@Constraint(validatedBy = {RequestParamsValidator.class})
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface IsValid {
    String[] params() default "";
    String message() default "{com.test.controller.validator.IsValid.message}";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}

public class RequestParamsValidator implements ConstraintValidator<IsValid, Params> {

    /* (non-Javadoc)
     * @see javax.validation.ConstraintValidator#initialize(java.lang.annotation.Annotation)
     */
    @Override
    public void initialize(IsValid constraintAnnotation) {
        validateItems = constraintAnnotation.params();
    }

    /* (non-Javadoc)
     * @see javax.validation.ConstraintValidator#isValid(java.lang.Object, javax.validation.ConstraintValidatorContext)
     */
    @Override
    public boolean isValid(Params value, ConstraintValidatorContext context) {
        try {
            for (String reqItem : validateItems) {
                final Object curObj = PropertyUtils.getProperty(value, reqItem);
                if (curObj == null || curObj.toString().isEmpty()) {    
                    return false;
                }
            }
        } catch (final Exception ignore) {
            // ignore
        }
        return true;
    }
}

Controller

@RequestMapping(method = RequestMethod.POST, value="", produces="application/json")
    public @ResponseBody BaseResponseDTO updateCustomer(@RequestBody @Valid UpdateCustomerRequestDTO requestDTO,
            BindingResult result) throws Exception {

        if (result.hasErrors()) {
            log.error("[Field] "+result.getFieldError().getField()+" [Message]"+ result.getFieldError().getDefaultMessage())
            // But here the result.getFieldError().getField() is returning params. Is there any way with which I can change it to params.customerId/parmas.userId
            return false
        }
        // add customer logic
    }