In the table on the right,
each row represents a single
property search expression.
The property drop down lists
an aggregate of all of the
properties for all of the types
selected within the object type list.
The matching expression is either
a simple string or a regular
expression matching the property's
value within the objects you seek.
When you have selected multiple
object types, entering an expression
for a property unique to only a
single type of object will inevitably
lead the search to respond only
with objects having that property
where that property matches the
provided expression.