The most common and most likely answer to this crossword clue is the 3 plus 6 plus 4 letter word RUB ELBOWS WITH
I've seen this crossword clue in Independent
R
U
B
E
L
B
O
W
S
W
I
T
H
Buddy explains!
The straight part
We know that "Be in the same social network as" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case be in the same social network as = rub elbows with.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.