JSFiddle - React, Tailwind, and code Playground

JavaScript

var x = {
    SubOfferGroups: [
        {
            AnswerOffersList: [
                { SalePrice: { DefaultValue: 6 } },
                { SalePrice: { DefaultValue: 10 } }
            ]
        },
        {
            AnswerOffersList: [
                { SalePrice: { DefaultValue: 5 } },
                { SalePrice: { DefaultValue: 2 } }
            ]
        },
        {
            AnswerOffersList: [
                { SalePrice: { DefaultValue: 15 } },
                { SalePrice: { DefaultValue: 9 } }
            ]
        }
    ],
    fnc: function ()
    {
        var valores = $(this.SubOfferGroups).map(function () {
            return $(this.AnswerOffersList).map(function () {
                return this.SalePrice.DefaultValue;
            }).get();
        }).get();
        
        var minValor = Math.min.apply(null, valores);
        
        return minValor;
    }
};

alert(x.fnc());