Changing LR File Location - How To Point LR to New Location

It was hard to see from your screenshot, but it seems that you may have a large number of separately shown folders appearing in the Folders panel. This is what happens if you have imported a lot of separate shoots, for each of which you have made a separate folder; but without any of the folder context showing which these folders share in common. The LR Folders panel is at root, a listing of all the different discrete locations that are involved in your pictures' storage on disk (it doesn't display your complete file system per se).

By using the "Show Parent Folder" option you can cause Lightroom to also display the containing folder for a given shoot folder. If other shoot folders also occur within the same parent folder, then these move automatically to nest inside that - to correspond with how these folders physically related in the real file system. That will still be valid for the new arrangement, assuming you have not re-organised or renamed things piecemeal but simply transferred everything together in one lump.

Typically everything does sit under a single overarching parent folder, either directly or with a small number of intermediate folders between - for example, I have a single location with "Year" folders within. Once those "year" folders are showing you have the ability to select and manage a whole year's worth of photos in one go, rather than a single folder's worth. And by using "Show Parent" on one of the "year" folders, I have my full structure showing. Or you may have used some other system, or none.

"top-level" merely means, so far as your photos are concerned, the folder they all are contained inside - it does not have to occur at the very top of the file system of your drive.

But once an overarching parent folder is showing, this becomes a point of management for a whole lot of photos. So that is what you would re-address (Find Missing Folder / Update Folder Location). Ideally, that will be it but sometimes there are more than one involved - e.g. necessarily, if photos sit on different drives then there has to be at least a separate top-level folder on each drive.

Lightroom can, as of some versions back, add parent folders into its listing even once the former full path has stopped being accessible. Because LR has a record of what that former full path was.