I have a need to link (2+) lists together to run a workflow. When a item is updated on one list, this triggers a series of events to update a line item within a separate list. The challenge right now is when you go to reference the second list ID, it only allows you select the dynamic ID from the current list you are in. Since the two items in separate lists will never have the same ID, you need to pull from a custom field within the first/second list. This will allow custom integration between various lists to create a very powerful SharePoint experience.
The only change you need is to allow for the second list ID to be dynamically assigned from one of the custom fields other than the ID field. This will require the custom field settings to be numeric and not alphanumeric. This option should also be available on other connectors. This will allow for multiple data sources to update items in other sources based on a numeric custom value field.
You are managing (10) projects within a SharePoint list "Project List". In another list, you track your purchase order information "POs". You utilize the Project List to track your financials such as committed spend and count of PO's and each project has a unique Project ID. You have one project that has multiple PO's for that single Project ID so multiple lines within the PO's list. Within the PO's list, you have a custom field where you reference the Project ID as your link between both lists. When you submit a new PO to the PO's list, it triggers a workflow. When that workflow is complete and the line item is set to approved status, you would like to update the Committed Spend and PO Count fields within the Project List list referencing the Project ID custom field. This would then provide you with an updated Committed spend and PO Count for that Project ID within the Project List. Next time you open the unique Project ID within the Project List, you will have the updated Committed Spend as well as a count of (1) PO tied to that line item.