慕 is built from the 莫 (not / sunset), 小, and 丶 (dot) components.
It belongs to a phonetic family with 模, 募, 暮, and 墓 — they share the 莫 component and the reading ボ.
A common word using 慕 is 慕う (したう), meaning “to yearn to adore”.
Don't confuse it with 模, 募, 暮, and 墓.