Is it possible to map parts of one data entity into parts of another data entity

Is it possible to map parts of one data entity into parts of another data entity within an expression rule?

I'm attempting to do so using the with{} function but receive a syntax error each time.
Has anyone else done something similair to this outside of a process node? Am wanting to use the expression rule to attempt to make the entities as dynamically updated as possible.


with(
local!entity1: rule!getEntity1FromDB(ri!id),
local!entity2: rule!getEntity2FromDB(ri!id),
local!entity1.fieldOne : local!entity2.fieldTwo,
local!entity1.fieldTwo : local!entity2.fieldFour,
local!entity1
)

Thanks in advance!

OriginalPostID-163769

OriginalPostID-163769