I have been searching and searching for an answer and thought i was close a few times but i have found myself at an impass. I have an rather complex approval workflow for my department, at the end of the flow i am working on creating a new item on a seperate site (both on prem) that communicates the changes that have been made. Part of this communication is providing the process(s) the change applies to and the L3 owner of those processs, which are both lookup columns to lists on that site. i have attempted multiple ways to send this information across but keep recieving errors on the action. my latest attempt has been to make exact copies of the lookup lists on the workflow site and have the workflow query the lists and retrieve the item ID(s) then send across the item ID(s) to the created item, this did not error but it left the field blank. Any assistance would be greatly appriciated and i can provide any additioal info if you have questions. thank you!
if both your sites are in a single site-collection, you could add your lookup fields as site-columns from the parent site. This way both sites have identical sources and you should be able to pass them no problem.
When they are two site collections:
When you copy your data, do you need the target-fields to be lookups as wells? Seems impractical to me to update the source lists on both ends when things get added / changed. If they do not need to be lookups, try copying the display text of the source-fields only.