Layout file for the iPhone 8 Plus logic board, Intel baseband version, in .bvr boardview format at 379 KB. The name separates it from the Qualcomm modem variant, whose board differs in the radio section, so confirm which modem your phone carries before probing. With a boardview you can search components by designator, highlight nets and trace rails such as the main supply line from the battery connector. It helps when locating a shorted capacitor, measuring diode values on connectors or finding where a signal leaves the CPU area.
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 @SMART_PHONE_SCHEMATICS. Enginerys does not host this file.
How to open a .bvr file
Text boardview from the BoardView R family of tools, seen for Lenovo, MSI and Clevo boards.