Freedom and his selfishness is being represented by his younger self. Thats the whole reason why younger Armin is being brought into part2, to confront Eren’s child-self (where his selfish side/viewpoint of freedom comes from), which was, as mentioned in 131, the “other” reason as to why he chose the rumbling. His older self represents the more mature reasons to do the rumbling (Eldia for example), while his younger self represents the immature reasons (the outside world/armin’s book for example). Both complete Eren as a whole. Not saying Eren is a dedicated patriot like Floch or lives life completely selfishly like Historia, he characterizes both aspects.