EtherealPlayer

I know this is probably very straightforward but I can’t seem to connect the dots.
I'm trying to pull the level of an ability to use in a formula, but don't know what to put in the data key.
Goal: I’m trying to bind the cost of upgrading an ability to its level, therefore I need the level of the ability for the formula calculation.
Example: Fireball level 1 cost 250 gold, using the research tree, upgrading fireball to level 2 cost 500, level 3, 750. Etc.
The formula I want to create = fireball's current level * 250.
How can I make the node Selected Data Level grab the fireball’s current level to calculate in the formula?
What do I have to put in the Data key to pull the fireball’s current level??

gamingislove

The learn costs of research items don't automatically have access to the ability. I.e. you'd need to first get the ability in the formula using a Select Ability node and can afterwards access it (using the data key you stored it into) via the Selected Data Level node.

Formulas that are used by the ability itself (e.g. use costs or user/target status changes) will have the ability available as selected data via the data key action.

EtherealPlayer

Thank you very much. That did it.
I was concerned that the Ability level in the Select Ability node would override the actual current level of the ability but that isn't the case.