If the repeated notes proceed from WEAK TO STRONG pulses, and if the other parts move in legato fashion or are held over, usually no tie is needed. If the other parts are repeated, a tie may be helpful in avoiding a "false" accent on a weak beat (see purple highlight).
If they proceed from STRONG TO WEAK, however, the possibilities divide themselves into four cases, depending on how many parts are repeated.
CASE 1. If ALL FOUR PARTS are repeated (measure 9 or 10):
CASE 2. If THREE of the four parts are repeated (measure 5 or 6), tie one or two of the three lower parts.
CASE 3. If TWO of the four parts are repeated (measure 3), tie none or one of the three lower parts.
CASE 4. If ONE of the four parts is repeated (bar line between measure 2 and 3), usually do not tie (even if the bar line were not present in this example). Index