Document current data flow of debug logging filtering

AdvLoggerPkg/Docs/ReadMe.md

@@ -247,6 +247,12 @@ and the follow change is needed in the .fdf:
 The v3 data header supports a new field of hardware debugging level to support setting the serial print configurable
 during boot time.
 
+All debug prints will be filtered by multiple build time flags, such as `PcdDebugPrintErrorLevel`, `MDEPKG_NDEBUG`, etc.
+Prints that pass such filters will be logged to memory, and then fed to the hardware port library to be checked
+against the hardware print level. A full data flow chart is shown below:
+
+![Debug Logging Level Filters](debug_log_level.png)
+
 The default value will be initialized to the value of `PcdAdvancedLoggerHdwPortDebugPrintErrorLevel` in the PEI core,
 DXE core, or MM core, whichever comes first during the boot process.