Just like the present perfect continuous, the past perfect continuous is also a very particular mood, used in reference to an action or state which had taken place before another action, while the narrator never witnessed it personally (note the construction of the past perfect continuous is dependent upon the past participle).

In Persian this mood is formed by the addition of the personal copulas to the past participle of the main verb, invariably followed by the past participle of the verb “to be,” that is, بوده:

While this mood is very sparingly used in English, it is used in Persian often. In colloquial Persian, the third copula is elided:

این را به تو گفته بوده اند ← این رُو به تو گفته بودن
in rā be to gofte budehand → in ro be to gofte budan
“They had said this to you.”

دکتر مادرش را دیده بوده است، امّا او خبر نداشته است ← دکتر مادرش رُو دیده بوده، امّا اون خبر نداشته
doctor mādaraš rā dide bude ast, amā xabar nadāšte ast →
doctor mādaraš ro dide bude, amā xabar nadāšte
“The doctor had seen her mother, but she had no idea.”

کسی به آنجا آمده بوده است، بدون این که پیغامی گذاشته باشد ← کسی اونجا اومده بوده، بدون این که پیغامی گذاشته باشه
kasi be ānjā āmade bude ast, bedun-e inke peyγāmi gozāšte bāšad →
kasi onjā umade bude, bedun-e inke peyγāmi gozāšte bāše
‘someone had come there without having left any messages’

In a very special historical narration, this mood is replaced with the present perfect, especially with the verb “to be,” and, in that, this mood does not correspond exactly to its construction in English in all occasions.

Compare and contrast the following sentences:

شاه قبلی شاه بهتری بوده است / شاه قبلی شاه بهتری بوده
šāh-e qabli šāh-e behtari bude ast/šāh-e qabli šāh-e behtari bude
“The previous king had (had) been a better one.”

شاه قبلی کارهای بهتری کرده بوده است
šāh-e qabli kārhaye behtari karde bude ast
“The previous king had (had) done a better job.”