1
general::
Also, wear a different hat or two hats; wear more than one hat. Function in a different or more than one capacity or position, as in I'm wearing another hat today; yesterday I was a housewife, today I'm an attorney, or I wear two hats? are you asking me as a member of the city council or as a storeowner? This metaphoric expression alludes to headgear worn for different occupations. [Mid-1900s]
American Heritage Idioms