The most common and most likely answer to this crossword clue is the 8 plus 1 plus 2 letter word SCREENED - DD
I've seen this crossword clue in The Times
S
C
R
E
E
N
E
D
-
D
D
Buddy explains!
The straight part
We know that "Involved in selection process/shown on TV" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case involved in selection process/shown on tv = screened - dd.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.