The word "loved" can either be an adjective or a verb. When you
say "loved ones", you are saying that the 'ones' are being loved.
You are using the adjective "loved". When you say something like "I
loved him", You are using the verb loved, the past tense of
loved.
The word love can either be a noun ( abstract noun) or a verb,
but not an adjective.
To me, "loved ones" the word "loved" is a
verb. But I went on to check the dictionary, I could
not find "loved" being a verb. Perhaps, I should
go check some English reference books.