@RavindraGande in the original post the product owner of that functionality commented that this feature is not supported:

" This is not a supported use case (Launch pad team can confirm this), the pick list configuration only supports list configured using table types. The record editor cannot support configuring a Auto Generated control with pre-defined settings. If you need a dynamic dropdown the alternative is to use a non-auto control.

The reason why it is not possible is the columns of the record editor are dynamic the record editor uses a Table (Grid) configuration that is bound to a ReportDefinition  (DataTableEditorReport for the data class)  and the columns sourced dynamically from RD Definition.

The way report definition column configuration works is it gets the control (control configured on column directly or on property ) configuration  and merges the configuration with control configuration on the column of the report definition page while doing so it will ignore editable configuration of the control and only merges the read only configuration (RD are supposed to displayed only in readonly) so any editable configuration done on the autogenerated control is lost.

"

 I have checked the Enhancement Request FDBK-27931 that is referenced in the forum post which you highlighted and it has not yet been actioned.