If you define your own join paths, use the RemoveAllTopics (Method) of the DefinedJoinPaths (Collection) to remove all topics based on the items on the Request and Limit lines. This method corresponds to selecting all available topics on the Define Join Path dialog box and removing the values in the Topics in Join Path list.
ActiveDocument.Sections["Query"].DataModel. JoinsOptions.DefinedJoinPath[“MyJoinPath“].RemoveAllTopics()
In the following example all topics are removed from the MyJoinPath join path:
ActiveDocument.Sections["Query"].DataModel.JoinsOptions.DefinedJoinPath[“MyJoinPath”].RemoveAllTopics()