I don’t think you can do that directly. What you can do is to look up the implementation of Blueprint, if you have the Engine source. I’m not sure what the best way is to find the correct function. What I’m usually doing, is hovering over the node to see the tooltip and then searching the Engine source for that text. This will be usually some comment right above the function that implements the blueprint node.
I also submitted a feature request, to add a “Go to implementation” option in the Blueprint editor: [Request] "Go to implementation" option for BP nodes - Programming & Scripting - Epic Developer Community Forums
However, some things are implemented differently by Blueprint nodes, then how you would do it in C++. Responding to user input is one of these things. That’s why I recommend checking out the C++ templates.