The spouses entered into a contract upon marriage

Upon marriage, the spouses entered into an agreement according to which the property acquired by each of them during the marriage period should relate to their separate property.
During their life together, the husband successfully engaged in business and, through the income received, acquired valuable property - a country house, a car, paintings, antiques, video equipment, etc. Wife devoted herself to housekeeping and parenting.
After several years of marriage, the marriage fell apart. Having divorced, the couple left, and two young children were left with their mother. When dividing the property, the wife, remembering the conditions of the marriage contract and fearing that her husband would refuse to pay funds for the maintenance of the children, took only the most necessary things with her - clothes, household utensils, food supplies. Three years later, after the dissolution of the marriage, the wife, on the advice of a lawyer, put to the former husband the question of the division of other property. He refused, explaining that under the terms of the contract all property that goes beyond what is necessary to support the family, belongs to him, that, finally, the division of property has already been made, and the wife missed the deadline for making any demands on him. He currently has a new family and he needs to think about how to provide for her.
How to solve the dispute?