Surfice only allosws the user to load one set of connectome nodes at a time. You can use a threshold on the color or intensity to only show some nodes and hide others. The simple solution is to write a Python script to concatenate nodes from multiple files as a single file for each image. It is easy to add support for multiple node files, but providing an intuitive user interface is tricky.

The other option is to use NiiVue that allows multiple independent node files.

https://niivue.github.io/niivue/features/labels.connectomes.html