e.g. John, who show the way to the lake, give us more directions.
Should it be show? or shows?
Thank you.

"John, who SHOWS the way to the lake, GAVE us more directions."

In the clause:
"…who shows (people) the way to the lake…"

'who' is the subject, and is singular because 'John' is singular, so we use the verb in the singular.