Hi
In Power BI Desktop, it's not supported to get data from an existing .PBIX file directly via Get Data option.
However, we can get another .PBIX file data in a new .PBIX file use below two methods:
a. Use Copy Table option to copy all table data. Then in a new .PBIx file, click Enter Data option, paste the table.
b. Export data from visual to a .CSV file. Then in a new .PBIX file, retrieve data from this .CSV file via Get Data->CSV. For more information, please refer to this article: Export data from Power BI visualizations.
If you have any question, please feel free to ask.
Best Regards,
Qiuyun Yu