Connect ... in ?

Hi~ As I know, the word "connect" is usually used with preposition "with" or "to".

Here I can't find the words except "in" which doesn't seem to make sense to me.

What is the structure of the part underlined?

Thank you for your help.

However, there is another type of genius—the individual who possesses a supreme level of expertise in more than one area. Many times this genius is able to connect a deep level of understanding in two unrelated fields leading to radical breakthroughs. A prime example of this is Leonardo da Vinci...