Hello it's me (again

) !
I used this to get a select filed with the list of user group :
{
xtype: 'modx-combo-usergroup' ,
renderer: true,
data: 'usergroup'
}
I'd like to do the same thing but with a list of chunks, but I can't find the data key for it.
I use Revo 2.2.1-dev
Thanks for your help !