If you are part of the group which you are addressing,的句子成份是

完整的句子应该是：
If you are part of the group which you are addressing,you will be in a position to know the experiences and problems which are common to all of you and it’ll be appropriate for you to make a passing remark about the inedible canteen food or the chairman’s notorious bad taste in ties.(2002 Text1)
【结构分析】本句包含由and连接两个并列分句.
第一个分句主干为you will be in a position,
不定式to know the experiences and problems 做定语,修饰position,
其中which引导定语从句,修饰the experiences and problems.
第二个分句为it’ll be appropriate for you to „,其中it作形式主语,
真正的主语为不定式to make a passing remark about„.
【参考译文】如果你是你谈话听众中的一员,你就能够了解你们所共有的经历和问题,而且你也可对餐厅极难吃的食物或者领导在选择领带方面差劲的品味进行评头论足.