interface PersonA {
    name: string,
    group: string,

    item1: string,
    item2: string,
}

interface PersonB {
    name: string,
    group: string,

    itemOne: string,
    itemTwo: string,
}

const personA: PersonA = {
    name: 'name',
    group: 'group',

    item1: 'item1',
    item2: 'item2',
}

const {
    item1,
    item2,
    ...partialPersonA
} = personA;

const personB: PersonB = {
    ...partialPersonA,
    itemOne: personA.item1,
    itemTwo: personA.item2,
}

console.log(personB)

/*
group: "group"
itemOne: "item1"
itemTwo: "item2"
name: "name"
*/