Multiple membership is more common in the case of individual sports, such as the sport of athletics, where a distance runner may compete for a track and field team as well as a road running team, and also have further membership at a local sports club for training purposes.
In the realm of individual sports, multiple affiliation is more typical, exemplified by the sport of athletics. A distance runner might participate in both a track and field team and a road running team, while also holding membership at a nearby sports club to support their training.