The media-modal which opens with the CMB-fields "file" or "file_list" does not show the attachment filter dropdown. If there is a big amount of files the search-filter-box on the right is not the best solution.
As a workaround you can use the Plugin https://de.wordpress.org/plugins/default-media-uploader-view/ which lets you preselect "Uploaded to this post". But then - because of the missing dropdown - you are not able to return to show all files ... ;)
The media-modal which opens with the CMB-fields "file" or "file_list" does not show the attachment filter dropdown. If there is a big amount of files the search-filter-box on the right is not the best solution.
As a workaround you can use the Plugin https://de.wordpress.org/plugins/default-media-uploader-view/ which lets you preselect "Uploaded to this post". But then - because of the missing dropdown - you are not able to return to show all files ... ;)