Its going to be a little more complicated than what you have there. What that bit of blueprint you have does is take the characters velocity, and takes that velocity and finds out how big it is.
Its good for getting speed, but doesn’t give you any direction info.
Your probably going to want to compare the forward vector of your character to your character’s velocity to find out what direction they are moving (relative to what they are facing.)
Its late and my logic is fuzzy, so I can’t do much more than point you (in hopefully) the right direction.