Selfishness is actually a rather complex topic. It’s also something that has become a contentious category within the past few decades. Here are two definitions:
“lacking consideration for other people; concerned chiefly with one’s own personal profit or pleasure”
“concerned excessively or exclusively with oneself : seeking or concentrating on one’s own advantage”
Now, the thing is, that people who have mental illness and trauma are often excessively or exclusively concerned with themselves. Their failures and their worthlessness take an outsized importance in their view of the universe. People with severe agoraphobia or social anxiety, for example, truly believe that their every little flaw and mistake is hugely obvious to and dwelled upon by other people.
Now is this kind of self-consciousness selfish?
Some people argue that it is, that Hinata’s actions to twice put herself in deadly danger with uncertain benefit were focused entirely on her own desire to do something for Naruto, not his own wishes or desires (and Hinata even calls herself selfish). But I don’t think it’s a fair or useful concept to apply to people who value themselves so little that they think their life can and should be thrown away like that.
I also believe that the post-699 material deliberately robbed Hinata of the growth she should have had in order to keep her “properly” dependant on Naruto. The “a man likes to feel like a man” way of pandering to males who are threatened by female competence and independence.
Rather than her choices, actions, and growth, The Last dwells excessively on Hinata’s genetic value as the “Byakugan Princess”. Just as Naruto is now a “child of prophecy”, he must have a prize wife who is just as marked out by destiny as special. Then together, because he has Asura-line genetics and she has Indra-line genetics, their children will have blah blah blah oh my GOD this interests me so little that I can’t go on.
But back to genin and Shippuden Hinata. I would not describe her as selfish per se in the “concerned with one’s profit or pleasure” in the typical sense. Rather, her worldview has been so distorted by her upbringing that she has an outsized sense of her own unimportance, which skews her actions in a self-oriented way.