Hey @Athuo135! Seems like your blueprint is based on a C++ class. So you won’t be able to adjust the hierarchy of the components from the editor.
To attach the camera component to the spring arm, all you need to do is this:
FollowCamera->SetupAttachment(CameraBoom);
If nothing changes after adding this code to your cpp file and compiling it, try closing the editor and building the project from VS.
Hope this helps! 