being decisive now 是一个分词短语作宾语 problem 的补足语.being decisive now 是一个系表结构的分词形式,其逻辑主语是句子的主语 he.而其完整的从句形式是 that he is being decisive now,如果把这个从句用在句中,就是 problem 的宾语同位语从句：
He is having a problem that he is being decisive now.