Group found in bed by the lake (7)
I believe the answer is:
coterie
'group' is the definition.
(term for a group of associated people)
'bed by the lake' is the wordplay.
'bed' becomes 'cot' (cot is a type of bed).
'by' is a charade indicator (letters next to each other).
'the lake' becomes 'erie' (Lake Erie is one of the Canadian/US 'Great Lakes').
'cot'+'erie'='COTERIE'
'found in' is the link.
(Other definitions for coterie that I've seen before include "Small exclusive group of people" , "Exclusive social circle" , "Exclusive group with shared interests" , "In-group" , "Small exclusive circle with a common purpose" .)