If you have two sets of variables, you can use Onyx’s node group functions to group variables together. Then you can connect the two groups with an each-to-each connection.
Select the first group of variables and click CTRL+1 (on Macs: CMD+1). This creates group #1. Select the second group of variables and click CTRL+2 (on Macs: CMD+2). This creates group #2. Now, right-click on any node from the first group and drag a path to any variable of the second group. This will create a path from each variable of the first group to each variable of the second group.