have been there several years ago的动词时态和时间状语有冲突,完成时的时间状语一般是一段时间,这句的时间状语一般是for several years.（类似的还有,since XX指从XX时间点到说话时的这段时间；already指“已经”,ever指"曾经",代表说话前的一段模糊的时间段,for XX指从说话时往后推XX长时间.）而且去过某地XX次正确表达是：have been to someplace for XX times.
有时候完成式和过去式的意思差别不是很大,像have been to someplace和went to someplace some time ago前者强调曾经去过某地这个事实,后者强调曾经过去这个动作,一个强调状态,一个强调动作,都是表达我去过某个地方.
have gone to指人已经走了.have been in someplace several years/ have been there for several years/ have been a teacher for several years是be in/ be there / be a teacher的完成式表示在某地已经呆了多久,做老师做了多久了的意思,have been to 是指去过某地,就差一个to,要小心区分.