Boardview archive for the Apple logic board 820-03160, about 192 KB, related in the index to boards 820-02536 and 820-03286. Apple identifies logic boards by these 820 numbers, which appear on the PCB, so verify the marking before use. The extracted layout opens in tools such as FlexBV or OpenBoardView, where you can locate components on both sides, highlight nets and find measurement points for voltage and diode-mode checks. It works best used together with the matching schematic for the same board number.
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 @cynetitsolution. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.