Hmm ... don’t block my view (3,2,3)
I believe the answer is:
let me see
This clue is a double definition.
'hmm' is the first definition.
(both can be used to express uncertainty)
'don't block my view' is the second definition.
(Other definitions for let me see that I've seen before include "Permit me to observe - I'm thinking" , "sit down in front there!" , "What do I do next" , "I must think about this" , "Hm" .)