I brought these things back from my holiday in Spain.

这个句子逻辑错误。修改如下：

I brought these things back from Spain.

back为副词作方向状语，from Spain为来源状语。

或者：

I came back from my holiday in Spain and I brought these things with me.

in Spain为holiday的定语，back为方向状语，from介词短语为来源状语。