Indicate variables from the Base Input SAS Data Set by which to merge data from the Merge Input SAS Data Set . The same variables must also exist in the Merge Input SAS Data Set .
Scroll through the Available Variables field to find the desired merge key variables.
Left-click to highlight a single variable. Hold down the key while left-clicking to select multiple variables.
Once you have selected the merge key variables, click the button to add them to the Merge Key Variables field.