Lenovo IdeaPad Z485 service archive referencing LZ2C, packed as a 1.97 MB RAR. The LZ2C label appears to be the internal board or project code tied to this AMD-based notebook, and it should be compared with the marking printed on the motherboard. Contents are likely a schematic set used for tracing power rails, checking the charger and EC circuitry and finding components on a shorted line. Extract with WinRAR or 7-Zip and verify the board number and revision before taking values from the drawings.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @generalschematics. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.