Once you've looked at that link, consider the following examples:
My brother and I are alike in our mannerisms.
(Our mannerisms are alike. Nothing else about us is necessarily alike.)
My brother and I are alike in that we both have a quirky sense of humor.
(Our quirky sense of humor is the same. Nothing else about us is necessarily the same.)
In both of these instances, "in xxxx" serves to LIMIT a statement. ("My brother and I are alike" means we're exactly alike"”in every imaginable way"”but "...are alike in X" means that we may or may not be alike in any other way besides X thing.)
In both instances, the green thing is either a noun or something that can act as a noun.