How to analyze a Moderated Mediation when DV is a within subjects?

#1
Hello everyone,
thank you in advance for advising me on the next.

I showed my participants, product pictures (3 products) - within-subject and I asked them to show their preference toward each. The same respondents were measured repeatedly for the 3 products (within factor too).

I'm trying to analyze the mediation effect of the consumer knowledge on preferences using a bootstrapping method.

The participants were divided into two groups, compared to their familiarity with the product, and I want to analyze the moderation effect of product familiarity on preferences through consumer knowledge.

I'll appreciate your help since I've searched a lot, buy my knowledge of statistics is poor.