excerpt

Main.cpp

// making my best effort, I think these code changes can get you the output you're looking for:
//
// there are 2 problems with the code. 
// The first happens on line 34 where you execute the PLayerGetGuess function (getting input) but don't store the value.

// to fix that problem, replace line 34 with: 
std::string PlayerGuess = PlayerGuessGet(); // store the PlayerGuess acquired by the PlayerGetGuess() function
// becuse you're intializing and storing this variable inside the PlayGame function, it is inaccessible outside the function, so...

// next, on line 35 you execute a function intended to print the PLayerGuess back to the console. 
// This is a bigger change, but you can make it work with these changes

// replace line 35 with:
PlayerGuessReturn(PlayerGuess); // pass the private variable to another function

// replace line 11 with:
void PlayerGuessReturn (std::string); // declare that the function requires a string argument

// delete line 49 - we do NOT want to call the Setter from the Getter
// and finally replace line 47 with:
void PlayerGuessReturn(PlayerGuessValue) // assign PlayerGuessValue the string passed to it

// Note: PlayerGuessValue is also a private variable of this function, and is not visible outside of the function

TL;DR :
replace line 11 in your Main.cpp with line 17 above
replace line 34 line 7 from above Gist
replace line 35 with line 14 from Gist
replace line 47 with line 21 from Gist
delete line 49 of your Main.cpp