OH3 Rule Next Gen: command item the state of another item

Hi. I cannot find the syntax to send a dynamic command to an item:
I have one item that stores the brightness I want to have (that changes during the day)
and I have another item that is the actual light bulb, controlled by a rule.
I want that rule to send the brightness (state of item) to the bulb.

I can do that with a script, but somehow I think there is a way to just post some form of syntax as a command, like shown in my picture.