For each advertising platform you use, pull raw spend data into separate Google Sheets using Supermetrics.
Use the Rename Node to relabel dimensions and metrics to get consistent column headings across the nodes. For example, Facebook calls marketing spend “Amount spent” and Google calls it “Cost”.
Create a new column called Country and populate it based on extracted data from the Campaign Name. Repeat for Channel and Objective.
Stack Datasets together using the Append Node to create a single marketing spend dataset.