Within the query you define the WHERE condition that is used of accessing the object. Inside the query you can reference values either directly of by accessing parent object attribute values.

Example: directly accessing data with IS:

xxx IS 'harry' AND yyy IS 'jo'

Example: accessing data with referencing parent object attribute

xxx1 IS ${PARENTNAME.yyy1} AND xxx2 IS ${PARENTNAME.yyy2}

Example: of course you can mix direct access and referenced access

xxx1 IS ${PARENTNAME.yyy1} AND xxx2 IS 'harry'

The following comparators can be used:

IS
LIKE
<
<=
>
>=

You may access context parameters (also referred to as "globals") by using the CONTEXT variable. For testing purposes you may add a direct value definition that is used if the context value is not available.

${CONTEXT.xxxx}
${CONTEXT.xxxx|...directValueIfNotSet...}

There are some pre-configured context parameters.