Complex sentence: Although the 50-Miler is an individual award, the requirements are performed as a group; where groups may be the troop, team or crew or a provisional group made of members of various units.
Split into simpler sentences: Although the 50-Miler is an individual award, the requirements are performed as a group. Groups may be the troop, team, crew, or an "ad hoc" group made of members of various units.