In the English Grammar Profile, B2 point 78 in the category of PAST is defined as:
past perfect continuous in relative clauses to give background information.
For example:
I was scrolling on social media,
and I saw a friend who had been sharing positive news stories.
A search in iWeb corpus for: who|that|which had been _vvg gives us
the most common continuous verbs found in past perfect continuous relative clauses:
1 WHO HAD BEEN WORKING 1233
2 WHO HAD BEEN LIVING 1080
One of our teachers who had been living in Peru
for many years
wanted to go back,
for the summer to help poor people.
Student speaking test example: TLC Spain B2
3 THAT HAD BEEN SITTING 642
4 THAT HAD BEEN GOING 481
5 WHO HAD BEEN WAITING 479
6 WHO HAD BEEN DRINKING 405
7 WHO HAD BEEN MISSING 399
8 WHO HAD BEEN USING 359
9 WHO HAD BEEN WATCHING 358
10 THAT HAD BEEN MISSING 341
11 WHO HAD BEEN PLAYING 325
12 WHO HAD BEEN TAKING 289
13 WHO HAD BEEN SITTING 287
14 WHO HAD BEEN TRYING 276
15 WHO HAD BEEN LOOKING 274
16 THAT HAD BEEN BUILDING 257
17 WHO HAD BEEN SERVING 246
18 WHO HAD BEEN STANDING 212
19 WHO HAD BEEN SUFFERING 208
20 WHO HAD BEEN RUNNING 196
WHO HAD BEEN FIGHTING
MMA Junkie22 WHO HAD BEEN FOLLOWING 184
23 THAT HAD BEEN WORKING 182
24 THAT HAD BEEN GROWING 175
25 THAT HAD BEEN RUNNING 171
26 WHO HAD BEEN SLEEPING 158
27 WHO HAD BEEN STUDYING 158
28 THAT HAD BEEN WAITING 153
29 WHO HAD BEEN DRIVING 152
30 WHO HAD BEEN MAKING 150
31 WHO HAD BEEN STAYING 149
WHICH HAD BEEN OPERATING
Boston 25 News33 WHICH HAD BEEN GOING 129
34 WHO HAD BEEN VISITING 123
35 WHO HAD BEEN HIDING 119
36 WHICH HAD BEEN RUNNING 115
37 WHO HAD BEEN RECEIVING 115
38 WHO HAD BEEN HOLDING 114
39 WHO HAD BEEN STRUGGLING 114
40 THAT HAD BEEN TAKING 112
41 THAT HAD BEEN LYING 112
It was a great big ocean liner
42 WHO HAD BEEN ATTENDING 112
THAT HAD BEEN HANGING
Women’s Health44 WHO HAD BEEN BATTLING 110
45 WHO HAD BEEN LISTENING 110
46 WHO HAD BEEN LEADING 109
47 THAT HAD BEEN PLAGUING 108
48 WHO HAD BEEN WALKING 106
49 THAT HAD BEEN HAPPENING 101
50 THAT HAD BEEN OPERATING 101
51 THAT HAD BEEN BREWING 101
52 WHO HAD BEEN HELPING 100
53 WHICH HAD BEEN SITTING 99
54 THAT HAD BEEN BOTHERING 97
55 WHO HAD BEEN DATING 93
56 WHO HAD BEEN PLANNING 91
57 WHO HAD BEEN SEARCHING 88
58 THAT HAD BEEN LIVING 87
59 THAT HAD BEEN LACKING 84
60 WHICH HAD BEEN WORKING 84
61 THAT HAD BEEN HOLDING 83
62 WHO HAD BEEN TEACHING 82
63 WHO HAD BEEN ACTING 80
64 WHO HAD BEEN TRAINING 79
65 THAT HAD BEEN PLAYING 78
66 WHO HAD BEEN TRAVELING 78
67 WHO HAD BEEN HOPING 77
68 WHO HAD BEEN TALKING 77
69 WHO HAD BEEN RIDING 75
70 THAT HAD BEEN USING 74
71 WHO HAD BEEN SELLING 74
72 THAT HAD BEEN MAKING 71
73 THAT HAD BEEN CAUSING 70
74 THAT HAD BEEN COMING 70
75 WHICH HAD BEEN BUILDING 70
76 WHO HAD BEEN PAYING 70
77 WHO HAD BEEN GOING 69
78 WHICH HAD BEEN GROWING 68
79 WHO HAD BEEN COMING 68
80 WHICH HAD BEEN LYING 66
81 WHO HAD BEEN TRAVELLING 65
82 WHO HAD BEEN EXPERIENCING 64
83 THAT HAD BEEN CIRCULATING 62
84 WHO HAD BEEN CONDUCTING 62
85 WHO HAD BEEN KEEPING 62
86 WHO HAD BEEN EXPECTING 61
87 WHO HAD BEEN SEEKING 61
88 WHO HAD BEEN TREATING 60
89 THAT HAD BEEN FLOATING 59
90 THAT HAD BEEN OCCURRING 58
91 WHO HAD BEEN LYING 58
92 THAT HAD BEEN DEVELOPING 57
93 WHO HAD BEEN INVESTIGATING 57
94 THAT HAD BEEN FOLLOWING 56
95 WHO HAD BEEN OPERATING 56
96 WHO HAD BEEN HANGING 55
97 WHO HAD BEEN GETTING 54
98 WHO HAD BEEN READING 54
99 WHO HAD BEEN WRITING 54
100 WHO HAD BEEN CALLING 53
B1 vocabulary in the top 50 hits above:
attending, fighting, hanging, hiding, leading, operating