Use Collectors to convert List to Map of Objects - Java

Use mapping as:

public Map<String, List<Team>> groupedByTeams(List<? extends GenericDAO> daoList) {
    Map<String, List<Team>> teamMap = daoList.stream()
            .collect(Collectors.groupingBy(GenericDAO::getTeam,
                    Collectors.mapping(this::convertGenericDaoToTeam, Collectors.toList())));
    return teamMap;
}

where a conversion such as convertGenericDaoToTeam could be possibly like:

Team convertGenericDaoToTeam(GenericDAO genericDAO) {
    return new Team(genericDAO.getId(), genericDAO.getName(), genericDAO.getType());
}

Your current collector - .collect(Collectors.groupingBy(GenericDAO::getTeam)) - is generating a Map<String,List<? extends GenericDAO>>.

In order to generate a Map<String, List<Pojo>>, you have to convert your GenericDAO instances into Pojo instances by chaining a Collectors.mapping() collector to the Collectors.groupingBy() collector:

Map<String, List<Pojo>> teamMap = 
    daoList.stream()
           .collect(Collectors.groupingBy(GenericDAO::getTeam,
                                          Collectors.mapping (dao -> new Pojo(...),
                                                              Collectors.toList())));

This is assuming you have some Pojo constructor that receives a GenericDAO instance or relevant GenericDAO properties.