The following does not seem to "indent" the second level itemization. The first level is indented correctly by 2em, but the second level is not indenting by 4em.
Troy Henderson
\setupindenting[no]
\setupitemgroup[itemize][1][][margin=2em]
\setupitemgroup[itemize][2][][margin=4em]
\starttext
Here is some text
\startitemize
\item Here is an item
\item Here is another item
\startitemize
\item Here is a sub-item
\item Here is another sub-item
\stopitemize
\stopitemize
\stoptext