Program View - Exporting dates columns to excel, return all values not just the single value. how to fix

Hi all.
I have a program view. this view includes connected boards from other projects only… each item is linked to another board with connected board and is showing different mirror columns.

One of the mirror columns is a date column, when I mirror it it shows me the earliest to latest (chose that). when export it to excel it shows all of the values of the mirrored column and not just the single date range presented in the program view. how can I fix it so the excel will look with one value. Thanks