Past Continuous:
“I was searching for a job in the newspaper when I got a phone call.”
or can I say:
“I was searching for a job when I finally got a job offered by my
previous employer.”
The second one sounds awkward to me. First, "got a job offered by" is not a phrasing that sounds natural to me. I would say "I was offered a job by" or (more colloquial) "got offered a job by". Second, a finer point, being offered a job does not lend itself well to the "instant in time" structure of your sentence. Normally a job offer tends to be something of a process in and of itself. You might say "I received an offer letter", which fits nicely into the format of something that can happen while you're doing something else.
This is partially because "I was searching for a job" sounds like a short-term state, as though you were actively on your computer reading through job postings. "Searching for a job" can be modified to make it sound like a longer term process. E.g. we can add the word "still" to make “I was still searching for a job when I was finally offered a job by my previous employer.” In the second instance, it has harmony again because the interrupting event is of a short duration relative to the ongoing action.
Past Perfect Continuous:
“I had been searching for a job for two months when I finally got a
job offered by my previous employer.”
Works for me, with the caveat above about job offer phrasing.
Past Perfect:
“I had searched for a new job before I got fired.”
Does it mean that I started to search for a job before I got fired and
finished before I got fired?
Yes. Of course, there's no answer implied to the question of why you stopped searching, so it's a little mysterious.
Present Perfect:
“I have searched for a new job for two months.”
This means I started to search two months ago and do no longer search
for a job right?
Not exactly, this sentence tells me that at some time in the past you spent two months looking for a job. The phrasing is most typically used to specify the duration of time you spend doing something. In other contexts it might replace the present perfect continuous. E.g. "I have worked on oil rigs for 10 years." is often said by someone who still works on oil rigs, just to emphasize his experience. "I searched for a new for for two months." does a better job of expressing that you spent two months searching and now you're done searching.
Present Perfect Continuous:
“I have been searching for a new job for two months.”
This means I started to search two months ago but I still search for a
job right?
Yes
