WGCNA modulePreservation on three expression sets

Question

[CTLong]

Hi,

I am interested in finding preserved modules across three conditions. As such, I performed WGCNA on each condition independently to obtain condition-specific modules. Now, I would like to use the modulePreservation function to identify modules that are preserved across the three conditions. However, I am aware that reference and test sets are required for this operation, and most of the examples I see online are only interested in studying two conditions (eg. WT vs Treated). Therefore in this case, given three conditions, how should I come about in approach this? Thanks.