Java applying filters on nested arrays?

I'm a beginner developer currently working in a startup as an intern, I have inherited the work of other developers, also interns, and I'm working on a web app.
The backend is in Java, I had never seen Java code before starting the internship 2 weeks ago, and therefore I have a lot of trouble reading and understanding the code sometimes, I have been stuck on this for the past 48 hours.

I have to make a function that filters profiles using a number of parmeters. Here's the function :

// Apply filters on our experts list
private List<UserExpertInfo> applyFilterOnUserExpertInfo(List<UserExpertInfo> experts, FiltersExpertsRequest filters) {
if (filters.isAvailable != null && filters.isAvailable == true ) {
experts.removeIf(e -> e.availability == false);
}
if (filters.name != null && !filters.name.equals("")) {
experts.removeIf(e -> !(e.firstName + e.LastName).contains(filters.name));
}
if (filters.maximumPrice != null) {
experts.removeIf(e -> !(filters.maximumPrice.longValue() >= e.wage.longValue()));
}
//  /!\ CAREFUL /!\ We can't have a NULL field in DB, or the removeIf function automatically returns NULL and the server sends back an error
if (filters.minimumRating != null) {
experts.removeIf(e -> !(filters.minimumRating.longValue() <= e.rating.longValue()));
}
// Expertises
if (filters.fluids != null && filters.fluids == true) {
experts.removeIf(e -> !e.expertises.fluids);
}
if (filters.thermic != null && filters.thermic == true) {
experts.removeIf(e -> !e.expertises.thermic);
}
if (filters.struct != null && filters.struct == true) {
experts.removeIf(e -> !e.expertises.struct);
}
if (filters.electro != null && filters.electro == true) {
experts.removeIf(e -> !e.expertises.electroMag);
}
// Areas
if (filters.aerospace != null && filters.aerospace == true) {
experts.removeIf(e -> !Arrays.asList(e.areas).contains("AEROSPACE"));
}
if (filters.industries != null && filters.industries == true) {
experts.removeIf(e -> !Arrays.asList(e.areas).contains("INDUSTRIES"));
}
if (filters.transport != null && filters.transport == true) {
experts.removeIf(e -> !Arrays.asList(e.areas).contains("TRANSPORT"));
}
if (filters.energy != null && filters.energy == true) {
experts.removeIf(e -> !Arrays.asList(e.areas).contains("ENERGY"));
}
// Languages : TODO
if (filters.languages != null) {
if (filters.languages.contains("english")) {
experts.removeIf(e -> !Arrays.asList(e.languages).contains("english"));
}
if (filters.languages.contains("spanish")) {
experts.removeIf(e -> !Arrays.asList(e.languages).contains("spanish"));
}
if (filters.languages.contains("french")) {
experts.removeIf(e -> !Arrays.asList(e.languages).contains("french"));
}
if (filters.languages.contains("german")) {
experts.removeIf(e -> !Arrays.asList(e.languages).contains("german"));
}
if (filters.languages.contains("italian")) {
experts.removeIf(e -> !Arrays.asList(e.languages).contains("italian"));
}
if (filters.languages.contains("dutch")) {
experts.removeIf(e -> !Arrays.asList(e.languages).contains("dutch"));
}
}
// Softwares : TODO 
return experts;
}

So, everything works pretty well, but i'm stuck at the Languages part. I can't seem to access the "name" field inside the "languages" array. Again pardon me if I misunderstand how Java works.
Here are the files on which this function relies on :

package fr.squad.zel.api;
import java.util.UUID;
public class UserExpertInfo {
public UUID userId;
public UUID expertId;
public String title;
public Number rating;
public Number wage;
public boolean availability;
public UUID photoUrl;
public String firstName;
public String LastName;
public Expertise expertises;
public String[] areas;
public RefSoftwares[] softwares;
public RefLanguages[] languages;
}

And

package fr.squad.zel.api;
import java.util.UUID;
public class RefLanguages {
public UUID id;
public String name;
}

And finally here is how I get my experts param (this is only the relevant part of the function) :

// Get expert's areas.
List<String> tempStringList = compoExpertsAreasServiceActions.findNamesByIdExpert(userTemp.getId());
userExpertTemp.areas = tempStringList.toArray(new String[tempStringList.size()]);
// Get expert's Softwares. 
List<RefSoftwares> tempSoftwaresList = compoExpertsSoftwaresService.findAllByExpertId(userTemp.getId());
userExpertTemp.softwares = tempSoftwaresList.toArray(new RefSoftwares[tempSoftwaresList.size()]);
// Get expert's Languages.
List<RefLanguages> tempLanguagesList = this.languageService.findAllByUserId(userTemp.getId());
userExpertTemp.languages = tempLanguagesList.toArray(new RefLanguages[tempLanguagesList.size()]);
return userExpertTemp;

The filters work fine, I have printed all of them. But I can't access the names of those languages, I really can't seem to grasp my head around the way those object work with eachother, and after a long time searching StackOverflow and other places, I really haven't been able to find a solution.

Looking at this:

        if (filters.languages.contains("english")) {
            experts.removeIf(e -> !Arrays.asList(e.languages).contains("english"));
        }

Inside the lambda, e.languages is a RefLanguages[]. You can access any of the individual elements by its index, then use the field name, eg e.languages[0].name. So you could write a loop to check for your thing. You can also use the stream api, eg replacing !Arrays.asList(e.languages).contains("italian") with Arrays.stream(e.languages).map(l -> l.name).noneMatch("italian"::equals)

But your code seems to say, if filters.languages is not null, then only keep the experts that speak all the languages.

So possibly, instead of duplicating the check for every language, you can put every language name into a set and test for inclusion:

experts.removeIf(e -> !Arrays.stream(e.languages)
                             .map(l -> l.name)
                             .collect(Collectors.toSet())
                             .containsAll(filters.languages));


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