THE USE OF THE PRESENT PERFECT CONTINUOUS

A. UNFINISHED ACTIONS
1/ To say how long for unfinished actions which started in the past and continue to the present. We often use this with 'for' and 'since' (see the present perfect simple page for more about 'for' and 'since').

-I've been living in London for two years.

-She's been working here since 2004.

-We've been waiting for the bus for hours.

This use is very similar to how we use the present perfect simple, and often it's possible to use either tense. Of course, with state (stative) verbs, we can't use the present perfect continuous.

-I've been here for hours.

NOT: II've been being here for hour haven’t been being here for hours.

2/ For temporary habits or situations. The action started in the past and continues to the present in the same way as with use number 1, but we don't answer the questions about 'how long' so clearly. Instead, we use a word like 'recently'.

-I've been going to the gym a lot recently.

-They've been living with his mother while they look for a house.

-I've been reading a lot recently.

This is very similar to the use of the present continuous for temporary habits and often either tense is possible.
B. FINISHED ACTIONS
3/Actions which have recently stopped (though the whole action can be unfinished) and have a result, which we can often see, hear, or feel, in the present. We don't use a time word here.

-I'm so tired, I've been studying.

-I've been running, so I'm really hot.

-It's been raining so the pavement is wet.

The present perfect simple has a very similar use, which focuses on the result of the action, whereas the present perfect continuous focuses on the action itself. See my page here about the difference between the present perfect simple and the present perfect continuous for more explanation.