【1】在表示具体的名词后接关系副词where引导定语从句是不可以省略的。

This is the house where Tom lived three years ago.

That is the park where Mike lost his wallet yesterday.

备注:以上引导定语从句的关系副词where不可以省略

【2】在表示模糊或者不确定的地点名词/地点副词后后接关系副词where引导定语从句是可以省略的。place，somewhere，anywhere，everywhere，nowhere

This is the place(where可省略)we worked together years ago.

这就是我们多年前一起工作的地方。

Have you somewhere(where可省略)I can lie down for an hour？

你有没有一个什么地方可以让我躺一个小时？

备注:以上引导定语从句的关系副词where是可以省略的

在回到网友的提供2个句子

【1】The building where he lives is very old.

【2】Do you know somewhere (where可省略) we can get a good meal?

备注:第1个句子where不可以省略，第2个句子where可以省略还可以用that/和in which替换。

【1】Do you know somewhere we can get a good meal?【正确】

【2】Do you know somewhere that we can get a good meal?【正确】

【3】Do you know somewhere where we can get a good meal?【正确】

【4】Do you know somewhere in which we can get a good meal?【正确】

备注:以上四种表达都是正确的。