What would customHelper do? Can’t you just do something like this instead?
in your initializer
export default {
initialize(container) {
const user = container.lookup('current-user:main');
Discourse.ajax("/some-url").then(result => user.set("isPartOfParticularGroup", true));
}
}
and in your .hbs file
{{#if currentUser.isPartOfParticularGroup}}
// your stuff
{{/if}