I don’t fully understand what your asking about tbh but i’ll try to give you my best insight so far.

So when having multi data dytpes on any single page bubble has built in “guide rails” that really only like to focus on one data type at a time so when you have a list of dogs inside of a class row than bubble isn’t natively built for you to search for the dogs list inside that cell. With that said when a user attaches a dog/run to a class you can create a text field with the dog/ run name in line or parallel with you attaching the dog or run object to the class and this text field will serve only the purpose to be searchable.

I apologize if my answer isn’t what your looking for. Maybe try adding some context or scrren shots to the thread and it could help us help you better.