It will depend on whether the part is simply set invisible (the Robin Hood Boots are a recent item that does that) which can be overridden with the eye icon in the Scene pane or by selecting the bone(s) and using the Visible setting in the parameters pane, or whether the clothes are GeoGrafted (the Genesis Women's Business Suit did that, though the G2F version didn't) in which case you would have to edit the auto hide group with the Geometry Edit tool.