Here is the label formula: LookUp(colLatestReview,galleryKey.Text = GalleryName, Max(ReviewYear)) where galleryKey.Text is employee name organized by last name, first name, GalleryName is Last Name First Name extracted from library folder paths.
The basic collection for the Review Library is: ClearCollect(colReviews,Filter('Employee Folder',"Performance Review" in 'Document Type'.Value));
The collection that adds review year to colReviews is: ClearCollect(colLatestReview,AddColumns(colReviews,"GalleryName",Mid('Folder path',Find("/",'Folder path')+1,Find("/",'Folder path',Find("/",'Folder path')+1)-Find("/",'Folder path',Find("/",'Folder path'))-1),"ReviewYear",Year('Date Completed')));
The Employee Folder library itself has a significant number of documents, but the collection filters to only performance reviews, which currently total 302. I have the data row limit set to 2000. Hope that helps.