I find difficult the past perfect continuous, so I looked for some real examples for practice it. I will give you reasons about why the writer used the past perfect continuous in this situation, for see if I am understanding that tense correctly or not and I would appreciate your feedback.
First, the concept:
"Past perfect continuous: uses
Continuing events in the past:
We use the past perfect continuous to talk about actions or events which started before a particular time in the past and were still in progress up to that time in the past:
We can use the past perfect continuous to talk about events which started before a time in the past and which finished, but where the effects or results were still important at a point in the past:"
(SOURCE: Cambridge Dictionary)
Now, the real example:
In this paragraph:
"Unrelated to the couple’s case, a third Australian is also being held in Evin prison, reportedly in solitary confinement. The Cambridge-educated academic had been lecturing at an Australian university before she was arrested last year. She has reportedly been tried – the charges are unknown – and sentenced to 10 years in jail."
(SOURCE: The Guardian)
"had been lecturing": It talks about an action or event in the past and was still in progress up to a particular time in the past. I ask: Which is the particular time in the past which stops her from giving lectures? My view about this is: "before she was arrested last year" gives me not too much reason for stops her from giving lectures because I could be arrested by the police and after a few hours of questions they could release me without charges for example, but in the sentence before the whole idea tells that those people are in Evin prison, so I suppose that one of them is the woman who was working at an Australian university, then, for me the whole idea in the sentence before is the particular time in the past.
If I am right, I did not know that I could build THE SAME tense mixed in more than one sentence, the example before, the past perfect continuous tense was built in two sentences. I ask: Is it possible or I am wrong?