Search Criteria for particular user?

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Hi,
We have developed an application in vbcs 
When logged into the application using username and password in which we get details related to that employee
We use business object to get table data, service data provider for filterCriteria.(Please find image for ref)
We have a search page in our application. 
When we give values for search criteria it works fine, but when we click button without
giving any criteria all the data are fetched.
We need only data related to that particular user.
 
How to achieve this.