String serachedWord = "bu"

List<IssuerExportsWrapper> exports;

public class IssuerExportsWrapper
{
   public Long id = null;
   public String name = null;
   public List<ContactExportsWrapper> allContactExports = new ArrayList<>();
}

public class ContactExportsWrapper
{
   public Long contactId;
   public String contactName;
   public List<ExportWrapper> allExportsForContact = new ArrayList<>();
}

public class ExportWrapper
{
   public Long id;
   public Long issuerId;
   public String filename;
}

name.toLowerCase().equalsIgnoreCase(serachedWord) || contactName.toLowerCase().equalsIgnoreCase(serachedWord) || filename.toLowerCase().equalsIgnoreCase(serachedWord)

for (int i = 0; i < HIERARCHY_DEPTH; i++) {
            stream = stream.flatMap(NamedLookupObjectWithChildren::flatter);
        }

        stream.filter(o -> query.equals(o.name()));

for (int i = 0; i < HIERARCHY_DEPTH; i++) {
            stream = stream.flatMap(NamedLookupObjectWithChildren::flatter);
        }

        stream.filter(o -> query.equals(o.name()));

public static final String serachedWord = "bu";

public static class IssuerExportsWrapper {
    
    public String name;
    
    public IssuerExportsWrapper(String name) {
        this.name = name;
    }
    
    @Override
    public boolean equals(Object obj) {
        return name.equalsIgnoreCase(((IssuerExportsWrapper)obj).name);
    }
}

public static void main(String[] args) throws Exception {
    List<IssuerExportsWrapper> a = new ArrayList<>();
    a.add(new IssuerExportsWrapper("au")); 
    a.add(new IssuerExportsWrapper("bu")); 
    a.add(new IssuerExportsWrapper("cu"));
    
    System.out.println(a.contains(new IssuerExportsWrapper(serachedWord)));
    System.out.println(a.indexOf(new IssuerExportsWrapper(serachedWord)));
}

List<IssuerExportsForAllContactsWrapper> tempReturn = new ArrayList<>();
String[] queryParts = filter.query.split(" ");

      for (int i = 0; i < exportsForAllContacts.size(); i++)
      {
         IssuerExportsForAllContactsWrapper issuerWrapper = exportsForAllContacts.get(i);
         if (issuerWrapper.issuerName.toLowerCase().contains(queryParts[0].toLowerCase())){
            tempReturn.add(issuerWrapper);
         }
         for (int j = 0; j < issuerWrapper.allExports.size(); j++)
         {
            ContactIssuerExportsWrapper contactWrapper = issuerWrapper.allExports.get(j);
            if (issuerWrapper.issuerName.toLowerCase().contains(queryParts[0].toLowerCase())){
               issuerWrapper = tempReturn.get(i);
               if (issuerWrapper==null){
                  tempReturn.add(issuerWrapper);
               }
               issuerWrapper.allExports.add(contactWrapper);
            }
            for (int k = 0; k <contactWrapper.allExportsForContact.size(); k++)
            {
               IssuerExportWrapper exportWrapper = contactWrapper.allExportsForContact.get(k);
               if (exportWrapper.filename.toLowerCase().contains(queryParts[0].toLowerCase())){
                  issuerWrapper = tempReturn.get(i);
                  if (issuerWrapper==null){
                     tempReturn.add(issuerWrapper);
                  }
                  contactWrapper = issuerWrapper.allExports.get(j);
                  if (contactWrapper==null){
                     tempReturn.get(i).allExports.add(contactWrapper);
                  }
                  tempReturn.get(i).allExports.get(j).allExportsForContact.add(exportWrapper);
               }
            }
         }
      }