About the meaning of "humility"
The meaning to humility seems to have two levels:
1. You don't always brag about your achievements. That's definitely a good quality, right?
2. A lack of self-esteem or a lack of ego. You always think other people are better than you. I wouldn't consider it as a good quality.
I'm not quite sure about the second usage. If it's right, can you give me some example? Thanks

Question

About the meaning of "humility"
The meaning to humility seems to have two levels:
 1. You don't always brag about your achievements. That's definitely a good quality, right?
2. A lack of self-esteem or a lack of ego. You always think other people are better  than you. I wouldn't consider it as a good quality.
I'm  not quite sure about the second usage. If it's right, can you give me some example? Thanks

Answer

Humility is defined as the quality or condition of being humble;  modest opinion or estimate of one's own importance, rank, etc. Pride is an antonym of humility.

For an example: many Asian cultures emphasize humility while American culture emphasizes pride and individuality.

Answer

Your first definition is correct; the second one really isn't.  That would be "excessively humble" (humble is the adjective form of humility).

There is a famous story of Winston Churchill saying about another politician:  "My opponent is a humble man, he is a man with much to be humble about!"

Answer

The second usage is not right. Someone with humility does not necessarily have any lack of self-esteem.