How to make a switch mirror coordinates Param?

I’m making a “Global Material” Blueprint for showcase my materials with easy to use parameters
I have a “global coordinates System” inside my “global Material” blueprint, I can easily scale, rotate, etc… through the parameter groups but I need to mirror/flip the coordinates in Vertical and Horizontal separately by a switch trough the parameter Groups, how can I do it, I know I’ts possible, I have done it in the past, but unfortunatly I’ve lost that blueprint in the UE 4.5 update, and I can’t remember how to do it again…

Can some one please help me on this one?

Best Regards