Filter array with another array
This is little neater IMO.



// User can be part of many groups
const user = {
  groups: ["group2"]
};

// Roles can have many groups
// What you see here is the output or 2 different data source
// Thats why we have group duplication inside different role
const roles = [{
  name: "role1",
  groups: [{
    id: "group1"
  }]
}, {
  name: "role2",
  groups: [{
    id: "group1"
  }, {
    id: "group2"
  }]
}];

const result = roles.filter(role =&gt; role.groups.find(group =&gt; user.groups.includes(group.id)));
console.log(result);