Hi Osman,
Sorry for the delay in getting back to you.
We have created a sample for your reference and kindly download the attached sample.
In this sample, we have created a Person object. We have added the Name property of type string to the custom object Person and we have used CustomEditor to display ComboBox for this string property.
For further details about creating CustomEditor in Property Grid, please refer the below link,
Please let us know if you have any queries.
Regards,
Narendran.M