Hi..

You can inject the services you need access to in the constructor, e.g.

private readonly IUmbracoContextAccessor _umbracoContextAccessor;

public SubscribeToEditorModelEvents(IUmbracoContextAccessor umbracoContextAccessor)
{
    _umbracoContextAccessor = umbracoContextAccessor;
}

and then using it like this:

var cache = _umbracoContextAccessor.UmbracoContext.Content;
var parent = cache.GetById(e.Model.ParentId);

I recently updated the documentation with an additional example using SendingMemberModel and injecting `IMemberGroupService. https://our.umbraco.com/documentation/reference/events/EditorModel-Events/#usage

/Bjarne