These manager gets that array inside array and sorted and separate from first letter

LetterManager.swift

protocol Letterable {
    var name: String { get }
}

final class LetterManager<T: Letterable> {
    
    // MARK : - Publics
    func getTheFirstLetters(with section: Int) -> String {
        var allTitles = [String]()
        
        for initials in dictionaryWithInitials {
            allTitles.append(initials.key)
        }
        if allTitles.indices.contains(section) {
            return allTitles[section]
        }
        return ""
    }
    
    var dictionaryWithInitials = [(key: String, value: [T])]()
    
    // MARK: - Privates
    private let datas: [T]
    private var initials = [String]() //Array that includes starter letter
    
    init(datas: [T]) {
        self.datas = datas
        getTheInitials(from: datas)
        filterInitialsDependsOnTheFirstLetter()
    }
    
    private func getTheInitials(from datas:[T]) {
        for brand in datas {
            // Need a check here, just in case
            let initial = "\(brand.name.capitalized.first!)"
            // If there is no initial letter add it
            if initials.contains(initial) == false {
                initials.append(initial)
            }
        }
    }
    
    private func filterInitialsDependsOnTheFirstLetter() {
        
        for initial in initials { //Başharflere göre markaları ayır
            let filteredBrands = datas.filter({ (brandObject) -> Bool in
                let first = "\(brandObject.name.capitalized.first!)"
                if first == initial {
                    return true
                }
                return false
            })
            let tuple = (initial,filteredBrands)
            dictionaryWithInitials.append(tuple)
        }
        
        self.dictionaryWithInitials = dictionaryWithInitials.sorted(by: { $0.0 < $1.0 }) //sort the array depends on the first letter
    }
    
}

// Usage
/*
struct SomeObject: Letterable {
    var name: String
}

let aldo = SomeObject(name: "Aldo")
let aldo2 = SomeObject(name: "Aldo2")
let baldo = SomeObject(name: "Baldo")
let caldo = SomeObject(name: "Caldo")

var datas : [SomeObject] = [aldo, aldo2, baldo, caldo]
let manager = LetterManager<SomeObject>(datas: datas)
manager.dictionaryWithInitials
manager.getTheFirstLetters(with: 2)
*/