Hi @Zolotoy
I'm sorry this may not be easy to implement. Excel has some limitations on exported reports. If the report item that controls whether another report item is switched is not located in the previous or next row/column of the report item that you are switching, the outline feature is also disabled.
For more details, you can refer to this link: https://learn.microsoft.com/en-us/sql/reporting-services/report-builder/exporting-to-microsoft-excel-report-builder-and-ssrs?view=sql-server-ver16.
If this answer was helpful, please mark it as "accept answer".
Best regards,
Aniya