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

You can use the dictionary syntax. For example:
ExpressionName: getMyNewType
inputs:
myCDT1 (Any Type),
myCDT2 (Any Type)
...
Definition: ={
cdt1: ri!myCDT1,
cdt2: ri!myCDT2,
anotherThing: "This is something else
}

Use:
with(
local!mergedData: rule!getMyNewType(cdt1, cdt2),
local!mergedData.cdt1.id
)

Oh how nifty! I'll try it, thank you!

Hello Jorge! I'm struggling a bit with implementing this. I understand the data dictionary but not fully on how it would allow me to map parts of cdt2 into parts of cdt1. The end goal would be to return the full entity of cdt1 with the updated fields, not just the updated fields. Also to note I will need to be updating around 10 fields.

Is this possible in Appian ? Is there somewhere I can read up on this topic more? Any further explanation is greatly appreciated.

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) **Both entites have fields that aren't being used, but in the end I will need to return the entire entity with the updated and non updated fields.

There is a plugin available to make that very easy. See forum.appian.com/.../summary