Hi Johann - yes, there is nothing special about the Manage Metadata view except it's an easy, holistic way to view all the fields in your data source. If you create a calculation here, then go through into a sheet to actually build a visualization, you will see the calculation in your Dimensions or Measures to the left. It functions exactly as a normal calculation would, you've just created it in a different place in the GUI.
Awesome, thanks Ben!
Sent from my Samsung Galaxy smartphone.