Create a secondary data connection to your defects list and while creating the data connection select Get data from SharePoint list. Then select your all your relevant column like Defect ID, Defect Details, and so on. Now the secondary data connection is ready.
Create two textbox columns, one to pass the input another one to display the result based on the input pass in the first text box (Defect ID).
Select the defect details text box in the form.
Click on the Default value Fx button.
Click on the insert field or Group
Select your secondary data connection from the data connection list.
Select the Defect Details from the Data Fields section
Click on the filter button
In the filter add selectDefectID (from list secondary data connection) -eq "DefectID(from the form textbox - where you will enter that textbox). Click 5 times OK, one after another.
Finally, filter should look like below:
Defect_x0020_Details[DefectID = SearchDefectByID]