Complex sentence: All BBS stations maintained primary affiliation with one of Canada's major networks--although BBS stations shared some programming as a distinct station group, BBS was only a supplementary affiliation, not a separate television network.
Split into simpler sentences: All BBS stations maintained primary affiliation with one of Canada's major networks. Although BBS stations shared some programming as a distinct station group, BBS was only a supplementary affiliation, not a separate television network.