Search for- include models and where query for included model

I have two table users and seekers (type of user) with a 1-1 relationship. To get the user information from a seeker, I will rely on the creator field. So I have no reference to the seekers in my users table. I want to get, from server-side, the seekers who have skills is in X and city = A where skill is a seeker’s attribute whereas city is a user’s attribute.
Firstly - how to make a research that would be somewhat equivalent to this (nodejs orm):
seekers = Seeker.findAll({
include: [
{model: User, where : {city: A}
}
],
skill: {$in: [X]}
})

I might be missing something but I feel like with bubble I could only get the users (or the seekers) from the back (with a search for + constraint) and then would need to perform, in the front-side, a filter of this list based on the other criteria. Basically this could be search for Users (constraint city = A):filtered (constraint skills in X). But this second step would be run front-side which I want to avoid.
Another way to not bother with all that would be to transfer the city attribute to the seekers table. But I really want to split between these 2 tables depending on the type of information, privacy etc.
What would you suggest doing?

2nd - I struggle figuring out how to set up the constraint “skills is in skills input’s value” as a seeker can actually have not one but multiple skills and I want to be able to retrieve any one that has at least one skills included in the skills I want to have.

3rd - all this makes me wonder how quick can a poor database design be fixed when using bubble? as i’m mainly focus on building mvp, it might not be necessary to try to have the best suited db. In my case I could simply put all fields that are used to look for seekers in the seekers table and then add a field of type seeker in my users table.

If only one question must be asked please answer the first one, I’ll do two other separate topics

I think a first mistake i made is to rely on the “creator” to refer to the user associated to the seeker. I instead manually added a user field of type user and now i can add in the constraint user in search for… which seems to make what i want. but don’t know if it’s the most performant way…