[NTG-context] setting margin for second level of itemize

Hi, I want items to display as follows (| represents the text area edge) | 1. First item | 2. Second item | 2.1 Sub item | 2.2 Sub item | 3. Third item I could not find a way to control the margin of the second level. Setting \setupitemize[1][margin=2em] \setupitemize[2][margin=4em] does not work. Thanks, Aditya