Hypothesis within level of random effect

Hello everyone

I have the following model:

Y ~ Group * Socialness + (Group * Socialness | Region) + (Socialness |
Subj1:Subj2) + (Socialness | mm(Subj1, Subj2)

Y is continuous
Group has 3 levels: HC (reference), SCZA, SCZB
Socialness has 2 levels: NonSocial (reference), Social
Region has 112 levels

I want, for example, to check an interaction hypothesis for whether the difference between SCZA and SCZB is different between the Social and NonSocial levels of the Socialness variable. Is this something I can do with the hypothesis function? I’m having quite some trouble coming up the the formula for this hypothesis. If not, what would be the best way to set-up conditional_effects() to look at this.

To complicate things more, I would like to check this hypothesis only at Region A (a single level of the random-effect Region). Is there a way to do this. I have been able to look at group within a region using conditional_effects(), but am having trouble setting up the best way to look at the interaction.

Any help is much appreciated.