showing the parent folder being the memory card
Then I am very sorry to suggest that the format of the card has permanently deleted your images.
Only the thumbnail previews may now exist in the catalog. ( An [!] indicating images as "missing" or [?] on a Folder.)
Right-click one thumbnail in the Library grid and select [Show in Explorer/Finder]- Where does Lightroom think your images are stored? I presume it will show the camera memory card as per the folder panel!
Did you make Backups of your images from the camera card to another hard-drive? (Not a catalog backup!)