He wanted his bed next to the window.

【翻译】他想要他的床靠近窗户。

从意思就可知道，next to the window 作宾语补足语。

这句话很简练，实际是：

He wanted his bed to stand/lie next to the window.

【提示】want 用作及物动词时, 可接名词、代词、动词不定式、动名词作宾语,也可接以形容词、现在分词、过去分词、动词不定式、介词短语、副词充当补足语的复合宾语。