Hi,
Try the following steps.
1. Go to text box properties.
2. Click on fx button.
3. Click on Insert field or group. Select ‘DeductionAmnt' from the secondary source.
4. Click Filter data. And click Add button.
5. Select ‘CodeDesc' in the first drop down, is equal to in the second drop down, and enter ‘Pension Join Service' text in the third drop down.
6. Click ok until all the windows gets closed.
Note: If you want to change the filter value, then its better to store that value in a field and while filtering compare with that value.