\defineenumeration[test][way=bysection]

% \defineenumeration[test]
% \setupenumeration [test][way=bysection]

\starttext
    \startsection[title=one]
        \starttest alpha \stoptest
        \starttest beta  \stoptest
    \stopsection
    \startsection[title=two]
        \starttest alpha \stoptest
        \starttest beta  \stoptest
    \stopsection
\stoptext
