Help with justifying aggregation in SPSS?

#1
Hi there,

I am running a multi-level model on data which is one row per individual survey return, each with Individual ID and Organisational ID. There are variables which can be aggregated in to group, but I first have to justify this aggregation, and have been told to do so via ICC(1), ICC(2) and Rwg. Although I can find a lot explaining what these are, I cannot seem to figure out how to do this is SPSS. I at first believed it came from the output of a one-way ANOVA, but have since been told it should be two-way.

Can anyone help me on this one? I can't see how I can do a two-way ANOVA as I surely only need to use the Organisational ID and aggregating variable in question?

Any help would be very gratefully received.
Thanks!