How to perform WABA

I am codnducting a research that requires the leader to evaluate the performance of his department members. my level of analysis is individual, however, I must first brove that it is the appropriate level of analysis. I need to calculate a within and between analysis (WABA) in order to examine the appropriate level. this is by comparing the within-group eta with the between-group eta. I am not sure really how to perform this analysis in SPSS. am I required to test for every group (one leader and his members)?