Though Mellon Financial Corp. has spent the last two years getting out of traditional banking, it says it still views its remaining retail components — private wealth management and Dreyfus Corp. — as keys to its growth picture. In recent months, Mellon has stressed that the December divestitures of its retail banking operation (to Citizens Financial Group ) and Dreyfus' online brokerage unit (to J.P. Morgan Chase & Co.) leave it with the right mix of growth and fee businesses. The deals leave the company with two retail businesses: Mellon Private Wealth Management (created Jan. 17 by combining the private asset management, private banking, and private mortgage divisions) and the rest of Dreyfus, a mutual fund company acquired in 1994.