Feature Selector Example
When you select the right-hand face of the model (blue), you can use that face to define a plane feature, or combine it with another planar face to define a width as the origin feature, depending on the design intent.
Click Location Dimension and select the face shown as the origin feature.
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Select the inner-left face of the notch as the tolerance feature. 
Location dimension with Notch selected in the feature selector as the tolerance feature type
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Location dimension with Plane selected in the feature selector as the tolerance feature type.
Click to place the location dimension and open the DimXpert PropertyManager.
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