Hopefully you can advise on this problem: We're trying to fit a three-level model (participants nested in classrooms nested in schools) where one of the steps involves a multigroup analysis (say, boys versus girls) combined with testing an indirect effect. Till now, we specified school and classroom as cluster variables and used TYPE=TWOLEVEL COMPLEX. None of the model variables were on the between-level so the model part is specified using %within% only.
The problem in the multiple group analysis is that people in the same cluster are assigned to different groups, something that is apparently not possible in Mplus: **For TYPE=TWOLEVEL COMPLEX with multiple groups, cluster IDs for the last cluster variable cannot appear in more than one group.**
Elsewhere in the forum you suggested using KNOWNCLASS and TYPE=TWOLEVEL MIXTURE but now the trouble is that the mediation part won't run: ** MODEL INDIRECT is not available for TYPE=TWOLEVEL MIXTURE.
Does you have advice on dealing with this? Many thanks in advance!!