You have selected the Outer and Inner Sources to be Blended into a single dataset, The Query Wizard allows you to define Join Conditions so you can link the matching data between the sources.

To Add Join conditions click on 'Add' and the Join Conditions form will open up.

If you wish to Edit or Delete any of your Query Conditions, select the condition by clicking on it in the list view.  Then click on either the Edit button or the Delete button.  If you click on the Edit button, this will open the Define Join Condition form.

Once you have defined your Query Filter Conditions click on the 'Next >' button to move on to the Query Wizard - Select Columns form.