Expose what nudists did on beach? (3,4)
I believe the answer is:
lay bare
'expose' is the definition.
(laying bare is a kind of exposing)
'nudists did on beach?' is the wordplay.
I cannot quite see how this works, but
'on' could be 're' ('on' can be mean 'with reference to') and 're' is found in the answer.
This explanation may well be incorrect...
'what' acts as a link.
Can you help me to learn more?
(Other definitions for lay bare that I've seen before include "Expose" , "Show clearly, disclose" .)