The most common and most likely answer to this crossword clue is the 7 letter word DELVING
I've seen this crossword clue in The Guardian
D
E
L
V
I
N
G
More clues leading to the result DELVING
Buddy explains!

The straight part
We know that "Searching" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case searching = delving.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.
What does DELVING mean?
DELVING verb- To dig the ground, especially with a shovel.
- To search thoroughly and carefully for information, research, dig into, penetrate, fathom, trace out
- To dig, to excavate.
- The act of one who delves.
- The shaking of tin ore in a sieve held underwater so that the waste flows out, leaving the tin behind.