cáng covers the full hide/store/collect range — physical concealment (隐藏), safekeeping (储藏), and curated collecting (收藏). For the noun sense storehouse / Tibet / Buddhist canon, switch to zàng.
memory
Grass radical 艹 on top: hiding things in the long grass. The lower 臧 supplies the sound and itself once meant 'to stash away' — sound and meaning reinforce each other.
Top grass radical — the variant of 草 used on plant and concealment chars. Hiding valuables or storing grain in tall vegetation is the semantic seed; the radical anchors that 'cover with growth' image.
Lower 臧 supplies the sound (zāng shifts to cáng/zàng via initial and tone change) and doubles as a semantic anchor — it originally meant 'to stash, store'. The same phonetic appears in 脏 (viscera).