There is a rule (which) aiming at anti-money laundery (that) forbid foreigners to send money to Europe. 这句中which应该去掉,就是现在分词修饰前面的rule。forbid改成forbids,这样的话就没有语法错误,分词短语和定语从句都是修饰同一个词。
英语中的确有两个定语从句修饰同一个先行词的情况。但是大多数情况下,我们写句子还是要尽量写自己可以掌控的,确保别人容易理解的。
There is a rule aiming at anti-money laundery, which forbids foreigners to send money to Europe.
或者:The rule which aims at anti-money laundery forbids foreigners to send money to Europe.
如果非要用两个定于从句修饰同一个先行词,也可以,但会比较拗口,不太符合习惯。