The Multivariate platform does only accept one input list. Once the dialog is run, correlations will be calculated on all pairwise X from the input list. Similarly when adding a Scatterplot to the multivariate analysis, all pairwise scatterplots will be shown.
However, in many situations there is an interest in only "correlating" and creating a scatterplot on a certain list of X variables versus another list of X (or Y) variables in terms of exploratory data analysis. Since all variables are always there this is a tedious task to scroll through that massive matrix of scatterplots in scenarios of wide datasets.
I'd appreciate to see two input lists for Multivariate with pairwise correlations/scatterplots from the variables in one list versus the variables in the other list.