Expose Variable to Matinee not working.

I’m trying to follow this tutorial:
https://docs.unrealengine.com/latest/INT/Engine/Matinee/UserGuide/BlueprintComponents/index.html

I get as far as adding an empty group then a variable to that group.
Nothing shows up though, I’ve tried various types of variables, all with ‘Expose to Matinee’ ticked.

Sorry guys, i’ve solved the problem.
I wasn’t selecting the blueprint i wanted to grab the variable from before making the empty track.