A quick stab:
これまで、社会における活動の主体は、国や地方の自治体等と民間企業中心となってきたが、今日では、これらの中間領域に位置する民間非営利団体による活動が活発になってきている。　

Until now, activities within the community were initiated(?) principally by the State or regional local governments or by private enterprise. These days, however, activities led by private NPOs, which fall somewhere in between these (the aforementioned) two categories, are intensifying.

Pretty rough - needs substantial polishing.
Anyway, hope to help a little :-)