New field name in field

I would like to rename or pass value to a field whose name is inside an other field.
field_value = “value”
field_name = “name_for_value”
I would like to create a field which is name_of_value with the value contained in field_value which would get the end result as:
name_of_value = “value”

Is this even possible as a step?

Would appreciate any help.