11g SOA : How to set Title for Composite

When you have thousands of transactions processed through SOA composite, it becomes almost impossible to find/audit any particular instance through EM console unless you have a way to query particular transaction through its business key.
One solution for this is to set  business key of transaction as title to the composite. Once this is done, you can use in built search functionality available in instances tab in em console.
In 11g, you can set the composite title without adding any Java embedded activity to the process definition.
Add an assign activity and set the property .
In From section,
1.select Type as “expression”
2. look for function in “Mediator Extension Functions” called setCompositeInstanceTitle

med:setCompositeInstanceTitle(concat("",<xpath for your variable>))

Note : For this to work, make sure you pass string to this function. You can either use string() or concatenate with “” to make it string as shown above.
In To section
1. Select Type as “property”.

2. select/enter : tracking.compositeInstanceTitle

Note : This property is not visible in available properties list, but will work once you add it.