English: This is my favourite English pop group, this is one of my favourite songs of thiers. Chinese: 这是我最喜欢的英国流行组合，这首歌是我最喜欢的他们的歌曲之一！ My translation is a bit different from you original version "这是我最爱的英国流行组合，这是我最喜欢他们的歌曲之一". I think the revised version sounds better.

the former sentence is rinht,but he last sentence has some problems,you can say"他们的歌曲是我最喜欢的歌曲之一".Can you understand

It should be:这是我最喜欢的英国流行组合，这首（歌）是他们歌曲中我的最爱之一！

这是我最喜欢的英国流行组合，他们的歌曲也是我最爱之一

for uns ,the native chinese speaker, we can understand what you want to say.but the sentence can be more chinese.so, it can be: 这是我最喜欢的英国流行组合。我喜欢他们的许多歌，这是其中之一。 the second sentence is harder to translate into a sentence in chinese.so ,i translate it into two sentences. whats more,in the first sentence, the word :爱。is not properly here. in my opinion,喜欢 is more properly. it seems there is a lot of mistakes in my writing.please correct it.thank you