You could use something like:
let obj = pm.response.json().users.find(e => e.name === 'Julius');
console.log(obj.pet);
You could use that function inside a test and expect against obj.pet
to equal iguana
.
For example:
pm.test('Name of pet matches', () => {
let obj = pm.response.json().users.find(e => e.name === 'Julius');
pm.expect(obj.pet).to.eql('iguana');
});