أُولٰئِكَ عَلَىٰ هُدًى مِنْ رَبِّهِمْ وَأُولٰئِكَ هُمُ الْمُفْلِحُونَ
Those are upon guidance from their Lord, and those are the successful. (Al-Baqarah 2:5)
«أُولٰئِكَ» refers back to the God-conscious people whose qualities have been stated. It thus supplies a link between prior description and predication: the earlier attributes are gathered into one recognized group, and guidance and success are then ascribed to them.
Repeating «أُولٰئِكَ» gives the success statement distinct prominence. The demonstrative does not itself mean “guidance” or “success”; those meanings belong to the predicates, while the pointing connects them to the described group.