请教英语高手，这句英语应该如何正确理解？最好能多举几个类似的例子！我对复杂点的句子理解答的好加分！

either...or...是一个句型
在这个固定搭配中，doing now 和have thought about doing 是并列的
也就是说，这两个词组都是修饰the things 的，来做它的后置定语。汉语意思是：“你正在做的事情或者你想做的事情”
如果你不理解这个长句子，可以先把定语从句you are either doing now or have thought about doing 省略掉，就变成了What are some of the things that are self-development activities?
这个句子又是一个定语从句，后面的 that are self-development activities也是修饰the things的。

What are some of the things you are either doing now or have thought about doing that are self-development activities?

该句中，you are either doing now or have thought about doing 应该视为前面 things 的定语从句，而其后的 that are self development activities 是 things 的另一个定语从句。

该句可以分解成为两个句子：
1.What are some of the things you are either doing or have thought about doing?
2.Waht are some of the things that are self-development activities?

you are either doing now or have thought about doing （你现在正在做的或者过去曾经想要做的）是some of the things 的定语，
that are self-development activities又是前面整句话What are some of the things you are either doing now or have thought about doing 的定语
大意：你现在正在做的或者过去曾经想要做的一些事都是自我完善的过程。

分解？这个句子是个复杂句。you are either doing ...activities 整个都是说明the things 的，定语从句中又包含一个从句 即 that are ... .但是就我个人而言，觉得这个that用的有点不合适哦。语法角度而言吧。

原句翻译：你正在做一些自我发展的活动或想过这样的一些东西吗?
have thought about doing that are ......是完成时的形式have+think(thought) about doing sth
you are either doing now.....sb+be动词+doing