Kind of vertical stack view & Extensions

UILabel+Multiline.swift

import UIView
extension UILabel {
    func markAsMultiline() {
        numberOfLines = 0
        lineBreakMode = .byWordWrapping
    }
}

UIView+ForceUpdateConstraints

import UIView
// MARK: - UIView + Force
extension UIView {
    func forceUpdateConstraint() {
        setNeedsUpdateConstraints()
        updateConstraints()
    }
}

VerticalStackView.swift

import UIView
// MARK: - VerticalStackView
@IBDesignable final class VerticalStackView: UIView {
    private weak var lblTitle: UILabel!
    private weak var lblDescr: UILabel!
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setup()
    }
    
    private func setupUI() {
        /*guard lblDescr == nil && lblTitle == nil else {
            return
        }*/
        assert(lblTitle == nil)
        let lblTitle = UILabel(frame: bounds)
        lblTitle.translatesAutoresizingMaskIntoConstraints = false
        lblTitle.font = .systemFont(ofSize: UIFont.smallSystemFontSize)
        lblTitle.markAsMultiline()
        addSubview(lblTitle)
        self.lblTitle = lblTitle
        
        assert(lblDescr == nil)
        let lblDescr = UILabel(frame: bounds)
        lblDescr.translatesAutoresizingMaskIntoConstraints = false
        lblDescr.font = .boldSystemFont(ofSize: UIFont.systemFontSize)
        lblDescr.markAsMultiline()
        addSubview(lblDescr)
        self.lblDescr = lblDescr
        
        directionalLayoutMargins = .init(top: 10,
                                         leading: 16,
                                         bottom: 10,
                                         trailing: 16)
        //can be compressed...
        lblDescr.setContentCompressionResistancePriority(lblTitle.contentCompressionResistancePriority(for: .vertical) - 1,
                                                         for: .vertical)
        
        //can be expanded description
        lblTitle.setContentHuggingPriority(lblDescr.contentHuggingPriority(for: .vertical) + 1,
                                           for: .vertical)
    }
    
    private func setupConstraints() {
        /*guard constraints.isEmpty else {
            return
        }*/
        
        assert(constraints.isEmpty)
        
        let dic: [String : Any] = ["title": lblTitle!,
                                   "desc": lblDescr!]
        //position description below title and take into account margins.
        let constrs = NSLayoutConstraint.constraints(withVisualFormat: "V:|-[title]-(vSpace)-[desc]-|",
                                       options: .alignAllLeading.union(.alignAllTrailing),
                                       metrics: ["vSpace": directionalLayoutMargins.top],
                                       views: dic)
         // title and description have same width..
        
        //full width constraint and margins..
        let hConstr = NSLayoutConstraint.constraints(withVisualFormat: "H:|-[title]-|",
                                                     metrics: nil,
                                                     views: dic)
        debugPrint("hConstr \(hConstr)")
        NSLayoutConstraint.activate([constrs, hConstr].flatMap { $0 })
    }

    private func setup(force: Bool = true) {
        setupUI()
        if force {
            forceUpdateConstraint()
        } else {
            setupConstraints()
        }
    }
    
    override func updateConstraints() {
        super.updateConstraints()
        guard constraints.isEmpty else {
            return
        }
        setupConstraints()
    }
    
    override func prepareForInterfaceBuilder() {
        super.prepareForInterfaceBuilder()
        
        // background to see
        backgroundColor = .yellow
        lblTitle.backgroundColor = .green
        lblDescr.backgroundColor = .blue
    
        //define content
        lblTitle.text = "Title Line One \n Line Two" // 2 lines..
        lblDescr.text = "Description Line One \n Line Two \n Line Three" // 3 lines..
    }
}

Create fake XIB (w/o adding to target & see results.)