How to find a role in a differnt guild discord.ks code example
Example 1: discord.js find role by name
let role = message.guild.roles.cache.find(role => role.name === "Rolename");
Example 2: discord.js get all members with role
//outputs the IDs of all members with the specified role as an array
// === discord.js v11 ===
message.guild.roles.get('ROLE-ID').members.map(m=>m.user.id);
// === discord.js v12 ===
message.guild.roles.cache.get('ROLE-ID').members.map(m=>m.user.id);