当定语从句的先行词是point，case，degree，position，activity，situation，stage，relationship等等抽象地点名词，表示某人或某物所处的情况或发展的阶段时，可以用关系副词where来引导。
定语从句的先行词是point（达到......程度）
We have reached a point where a change is needed.
定语从句的先行词是case（在......情形之下）
There are cases where the word‘mighty’is used as all adverb.
定语从句的先行词是position（在......情况下）
It is put me in a position where I can't afford to take the job.
定语从句的先行词是activity（在......活动范围中）
Those successful deaf dancers think that dancing is an activity where sight matters are more than hearing.
定语从句的先行词是situation（在......境地）
He got into a situation where it is hard to decide what is right and wrong.
定语从句的先行词是relationship（在......关系中）
Remember that the best relationship is onewhere your love for each other is great.
定语从句的先行词是stage（在......阶段）
Until today, we have reached a stage where we have almost no rights at all.
可以的，在定语从句中做关系副词。
定语从句where用法总结及例句讲解如下：
1. where可引导限制性定语从句和非限制性定语从句，指代表示地点的先行词，在从句中作状语
The town where she lives is very small.
她所居住的小镇非常小。
【where指代地方（in the town），在从句中作状语】
This is the room where the nanny sleeps.
这个房间是保姆睡觉的地方。
【where指代地方（in the room），在从句中作状语】
My son attends the school where I teach.
我儿子在我教书的学校上学。
【where指代地方（in the school），在从句中作状语】
In 2008, we moved to New York, where my parents lived.
2008年，我们移居纽约，我的父母住在那里。
【where指代地方（in New York），在从句中作状语】
This is the place, where I used to hide the money.
就是这个地方，我以前经常把钱藏在这里。
【where指代地方（at the place），在从句中作状语】
2. 限制性定语从句中，当先行词是place时，where可以省略
This is the place where I was born.
这就是我出生的地方。
= This is the place I was born.
3. where经常可与 in/at/on which等替换使用
This is the room where she found the victim’s body.
这就是她发现受害者尸体的房间。
=This is the room in which she found the victim’s body.
This is the train station where they arrive.
这就是他们到达的火车站。
= This is the train station at which they arrive.
This is the playing field where football is played.
这就是踢足球的运动场。
= This is the playing field on which football is played.
以上就是定语从句where的用法的简单的总结，希望对你有所帮助！